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Why does Solve lock up when trying to solve the quadratic equation with large integers?


Why does repeating an equation help in FindRoot?Why does Mathematica fail to solve my equation?How to solve this equation with integers as a solution?Mathematica Solve function does not solve double exponentialEquation is solved quickly using Solve but takes too long using NSolveSolve gives duplicate solutions for a particular equationSolveAlways keeps on loadingSolve an exponential equation in integersUnexpected behaviour with FindInstanceWhy does NDSolve work with an initial condition but not a final condition?













4












$begingroup$


Why does Solve lock up when trying to solve the equation



Solve[(x^2+y^2)+(x+y)==2^511 && x>0 && y>0,x,y,Integers]


It works up 2^185, but at higher powers of 2, it seems to stop processing. The program says it's running, but there is no solution after running overnight. Running Mathematica 11.3 on Windows 32-bit OS.










share|improve this question









New contributor




user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    You can format inline code and code blocks by selecting the code and clicking the button above the edit window. The edit window help button ? is useful for learning how to format your questions and answers. You may also find this meta Q&A helpful
    $endgroup$
    – Michael E2
    Mar 10 at 18:27






  • 1




    $begingroup$
    I quickly get solutions for 2^257 (V11.3.0, macos).
    $endgroup$
    – Michael E2
    Mar 10 at 18:29










  • $begingroup$
    Sorry, there was a typo - it should be 2^511
    $endgroup$
    – user63373
    Mar 10 at 19:21






  • 1




    $begingroup$
    Probably it's combinatorial blowup. n = 185 gives 32 solutions but n = 257 already gives 1024. Might be more work and memory to store the symbolics than your CPU can handle.
    $endgroup$
    – b3m2a1
    Mar 10 at 19:38







  • 2




    $begingroup$
    @b3m2a1 I think the reasons probably have to do with number theory. n = 323 produces 8192 solutions in 2.3s and n = 325 produces only 128 solutions in 500s. The memory growth is quite low. I think for n = 511, you just have to wait long enough, and I can't predict how long that is.
    $endgroup$
    – Michael E2
    Mar 10 at 19:57















4












$begingroup$


Why does Solve lock up when trying to solve the equation



Solve[(x^2+y^2)+(x+y)==2^511 && x>0 && y>0,x,y,Integers]


It works up 2^185, but at higher powers of 2, it seems to stop processing. The program says it's running, but there is no solution after running overnight. Running Mathematica 11.3 on Windows 32-bit OS.










share|improve this question









New contributor




user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    You can format inline code and code blocks by selecting the code and clicking the button above the edit window. The edit window help button ? is useful for learning how to format your questions and answers. You may also find this meta Q&A helpful
    $endgroup$
    – Michael E2
    Mar 10 at 18:27






  • 1




    $begingroup$
    I quickly get solutions for 2^257 (V11.3.0, macos).
    $endgroup$
    – Michael E2
    Mar 10 at 18:29










  • $begingroup$
    Sorry, there was a typo - it should be 2^511
    $endgroup$
    – user63373
    Mar 10 at 19:21






  • 1




    $begingroup$
    Probably it's combinatorial blowup. n = 185 gives 32 solutions but n = 257 already gives 1024. Might be more work and memory to store the symbolics than your CPU can handle.
    $endgroup$
    – b3m2a1
    Mar 10 at 19:38







  • 2




    $begingroup$
    @b3m2a1 I think the reasons probably have to do with number theory. n = 323 produces 8192 solutions in 2.3s and n = 325 produces only 128 solutions in 500s. The memory growth is quite low. I think for n = 511, you just have to wait long enough, and I can't predict how long that is.
    $endgroup$
    – Michael E2
    Mar 10 at 19:57













4












4








4


1



$begingroup$


Why does Solve lock up when trying to solve the equation



Solve[(x^2+y^2)+(x+y)==2^511 && x>0 && y>0,x,y,Integers]


It works up 2^185, but at higher powers of 2, it seems to stop processing. The program says it's running, but there is no solution after running overnight. Running Mathematica 11.3 on Windows 32-bit OS.










share|improve this question









New contributor




user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




Why does Solve lock up when trying to solve the equation



Solve[(x^2+y^2)+(x+y)==2^511 && x>0 && y>0,x,y,Integers]


It works up 2^185, but at higher powers of 2, it seems to stop processing. The program says it's running, but there is no solution after running overnight. Running Mathematica 11.3 on Windows 32-bit OS.







equation-solving number-theory diophantine-equations






share|improve this question









New contributor




user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 2 days ago









J. M. is slightly pensive

97.9k10304464




97.9k10304464






New contributor




user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked Mar 10 at 18:23









user63373user63373

233




233




New contributor




user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






user63373 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







  • 1




    $begingroup$
    You can format inline code and code blocks by selecting the code and clicking the button above the edit window. The edit window help button ? is useful for learning how to format your questions and answers. You may also find this meta Q&A helpful
    $endgroup$
    – Michael E2
    Mar 10 at 18:27






  • 1




    $begingroup$
    I quickly get solutions for 2^257 (V11.3.0, macos).
    $endgroup$
    – Michael E2
    Mar 10 at 18:29










  • $begingroup$
    Sorry, there was a typo - it should be 2^511
    $endgroup$
    – user63373
    Mar 10 at 19:21






  • 1




    $begingroup$
    Probably it's combinatorial blowup. n = 185 gives 32 solutions but n = 257 already gives 1024. Might be more work and memory to store the symbolics than your CPU can handle.
    $endgroup$
    – b3m2a1
    Mar 10 at 19:38







  • 2




    $begingroup$
    @b3m2a1 I think the reasons probably have to do with number theory. n = 323 produces 8192 solutions in 2.3s and n = 325 produces only 128 solutions in 500s. The memory growth is quite low. I think for n = 511, you just have to wait long enough, and I can't predict how long that is.
    $endgroup$
    – Michael E2
    Mar 10 at 19:57












  • 1




    $begingroup$
    You can format inline code and code blocks by selecting the code and clicking the button above the edit window. The edit window help button ? is useful for learning how to format your questions and answers. You may also find this meta Q&A helpful
    $endgroup$
    – Michael E2
    Mar 10 at 18:27






  • 1




    $begingroup$
    I quickly get solutions for 2^257 (V11.3.0, macos).
    $endgroup$
    – Michael E2
    Mar 10 at 18:29










  • $begingroup$
    Sorry, there was a typo - it should be 2^511
    $endgroup$
    – user63373
    Mar 10 at 19:21






  • 1




    $begingroup$
    Probably it's combinatorial blowup. n = 185 gives 32 solutions but n = 257 already gives 1024. Might be more work and memory to store the symbolics than your CPU can handle.
    $endgroup$
    – b3m2a1
    Mar 10 at 19:38







  • 2




    $begingroup$
    @b3m2a1 I think the reasons probably have to do with number theory. n = 323 produces 8192 solutions in 2.3s and n = 325 produces only 128 solutions in 500s. The memory growth is quite low. I think for n = 511, you just have to wait long enough, and I can't predict how long that is.
    $endgroup$
    – Michael E2
    Mar 10 at 19:57







1




1




$begingroup$
You can format inline code and code blocks by selecting the code and clicking the button above the edit window. The edit window help button ? is useful for learning how to format your questions and answers. You may also find this meta Q&A helpful
$endgroup$
– Michael E2
Mar 10 at 18:27




$begingroup$
You can format inline code and code blocks by selecting the code and clicking the button above the edit window. The edit window help button ? is useful for learning how to format your questions and answers. You may also find this meta Q&A helpful
$endgroup$
– Michael E2
Mar 10 at 18:27




1




1




$begingroup$
I quickly get solutions for 2^257 (V11.3.0, macos).
$endgroup$
– Michael E2
Mar 10 at 18:29




$begingroup$
I quickly get solutions for 2^257 (V11.3.0, macos).
$endgroup$
– Michael E2
Mar 10 at 18:29












$begingroup$
Sorry, there was a typo - it should be 2^511
$endgroup$
– user63373
Mar 10 at 19:21




$begingroup$
Sorry, there was a typo - it should be 2^511
$endgroup$
– user63373
Mar 10 at 19:21




1




1




$begingroup$
Probably it's combinatorial blowup. n = 185 gives 32 solutions but n = 257 already gives 1024. Might be more work and memory to store the symbolics than your CPU can handle.
$endgroup$
– b3m2a1
Mar 10 at 19:38





$begingroup$
Probably it's combinatorial blowup. n = 185 gives 32 solutions but n = 257 already gives 1024. Might be more work and memory to store the symbolics than your CPU can handle.
$endgroup$
– b3m2a1
Mar 10 at 19:38





2




2




$begingroup$
@b3m2a1 I think the reasons probably have to do with number theory. n = 323 produces 8192 solutions in 2.3s and n = 325 produces only 128 solutions in 500s. The memory growth is quite low. I think for n = 511, you just have to wait long enough, and I can't predict how long that is.
$endgroup$
– Michael E2
Mar 10 at 19:57




$begingroup$
@b3m2a1 I think the reasons probably have to do with number theory. n = 323 produces 8192 solutions in 2.3s and n = 325 produces only 128 solutions in 500s. The memory growth is quite low. I think for n = 511, you just have to wait long enough, and I can't predict how long that is.
$endgroup$
– Michael E2
Mar 10 at 19:57










1 Answer
1






active

oldest

votes


















8












$begingroup$

Here's a guess:
The Diophantine problem
$$ x^2+y^2+x+y=a$$
is equivalent, via $u=2x+1,v=2y+1$ to finding the odd solutions to
$$u^2+v^2=2+4a ,.$$
Whether Solve makes this transformation or not,
solving the Pythagorean equation can be done from the prime factorization of $2+4a$.
How long Solve takes thus might depend on how long it takes to factor $2+4a$.



This is not hard to verify:



Block[FactorInteger = (Print["FactorInteger"[##]]; Abort[]) &,
PrintTemporary@Dynamic@Clock@Infinity;
Print[2 + 4 2^325];
Solve[(x^2 + y^2) + (x + y) == 2^325 && x > 0 && y > 0, x, y, Integers] // AbsoluteTiming
]



 2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730

FactorInteger[
2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730]

$Aborted



Well, it turns out it takes about 500 sec. to factor 2 + 4 * 2^325, which is about how long it takes the Solve above to run.






share|improve this answer









$endgroup$












  • $begingroup$
    Thank you very much. This seems to be exactly what is happening. Much appreciated.
    $endgroup$
    – user63373
    Mar 10 at 21:19










  • $begingroup$
    @user63373 You're welcome. :)
    $endgroup$
    – Michael E2
    Mar 10 at 22:10










Your Answer





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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









8












$begingroup$

Here's a guess:
The Diophantine problem
$$ x^2+y^2+x+y=a$$
is equivalent, via $u=2x+1,v=2y+1$ to finding the odd solutions to
$$u^2+v^2=2+4a ,.$$
Whether Solve makes this transformation or not,
solving the Pythagorean equation can be done from the prime factorization of $2+4a$.
How long Solve takes thus might depend on how long it takes to factor $2+4a$.



This is not hard to verify:



Block[FactorInteger = (Print["FactorInteger"[##]]; Abort[]) &,
PrintTemporary@Dynamic@Clock@Infinity;
Print[2 + 4 2^325];
Solve[(x^2 + y^2) + (x + y) == 2^325 && x > 0 && y > 0, x, y, Integers] // AbsoluteTiming
]



 2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730

FactorInteger[
2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730]

$Aborted



Well, it turns out it takes about 500 sec. to factor 2 + 4 * 2^325, which is about how long it takes the Solve above to run.






share|improve this answer









$endgroup$












  • $begingroup$
    Thank you very much. This seems to be exactly what is happening. Much appreciated.
    $endgroup$
    – user63373
    Mar 10 at 21:19










  • $begingroup$
    @user63373 You're welcome. :)
    $endgroup$
    – Michael E2
    Mar 10 at 22:10















8












$begingroup$

Here's a guess:
The Diophantine problem
$$ x^2+y^2+x+y=a$$
is equivalent, via $u=2x+1,v=2y+1$ to finding the odd solutions to
$$u^2+v^2=2+4a ,.$$
Whether Solve makes this transformation or not,
solving the Pythagorean equation can be done from the prime factorization of $2+4a$.
How long Solve takes thus might depend on how long it takes to factor $2+4a$.



This is not hard to verify:



Block[FactorInteger = (Print["FactorInteger"[##]]; Abort[]) &,
PrintTemporary@Dynamic@Clock@Infinity;
Print[2 + 4 2^325];
Solve[(x^2 + y^2) + (x + y) == 2^325 && x > 0 && y > 0, x, y, Integers] // AbsoluteTiming
]



 2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730

FactorInteger[
2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730]

$Aborted



Well, it turns out it takes about 500 sec. to factor 2 + 4 * 2^325, which is about how long it takes the Solve above to run.






share|improve this answer









$endgroup$












  • $begingroup$
    Thank you very much. This seems to be exactly what is happening. Much appreciated.
    $endgroup$
    – user63373
    Mar 10 at 21:19










  • $begingroup$
    @user63373 You're welcome. :)
    $endgroup$
    – Michael E2
    Mar 10 at 22:10













8












8








8





$begingroup$

Here's a guess:
The Diophantine problem
$$ x^2+y^2+x+y=a$$
is equivalent, via $u=2x+1,v=2y+1$ to finding the odd solutions to
$$u^2+v^2=2+4a ,.$$
Whether Solve makes this transformation or not,
solving the Pythagorean equation can be done from the prime factorization of $2+4a$.
How long Solve takes thus might depend on how long it takes to factor $2+4a$.



This is not hard to verify:



Block[FactorInteger = (Print["FactorInteger"[##]]; Abort[]) &,
PrintTemporary@Dynamic@Clock@Infinity;
Print[2 + 4 2^325];
Solve[(x^2 + y^2) + (x + y) == 2^325 && x > 0 && y > 0, x, y, Integers] // AbsoluteTiming
]



 2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730

FactorInteger[
2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730]

$Aborted



Well, it turns out it takes about 500 sec. to factor 2 + 4 * 2^325, which is about how long it takes the Solve above to run.






share|improve this answer









$endgroup$



Here's a guess:
The Diophantine problem
$$ x^2+y^2+x+y=a$$
is equivalent, via $u=2x+1,v=2y+1$ to finding the odd solutions to
$$u^2+v^2=2+4a ,.$$
Whether Solve makes this transformation or not,
solving the Pythagorean equation can be done from the prime factorization of $2+4a$.
How long Solve takes thus might depend on how long it takes to factor $2+4a$.



This is not hard to verify:



Block[FactorInteger = (Print["FactorInteger"[##]]; Abort[]) &,
PrintTemporary@Dynamic@Clock@Infinity;
Print[2 + 4 2^325];
Solve[(x^2 + y^2) + (x + y) == 2^325 && x > 0 && y > 0, x, y, Integers] // AbsoluteTiming
]



 2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730

FactorInteger[
2734063405978764905465627783897026706691461788616515545532213258012441248999219
90402939147127881730]

$Aborted



Well, it turns out it takes about 500 sec. to factor 2 + 4 * 2^325, which is about how long it takes the Solve above to run.







share|improve this answer












share|improve this answer



share|improve this answer










answered Mar 10 at 20:38









Michael E2Michael E2

149k12200479




149k12200479











  • $begingroup$
    Thank you very much. This seems to be exactly what is happening. Much appreciated.
    $endgroup$
    – user63373
    Mar 10 at 21:19










  • $begingroup$
    @user63373 You're welcome. :)
    $endgroup$
    – Michael E2
    Mar 10 at 22:10
















  • $begingroup$
    Thank you very much. This seems to be exactly what is happening. Much appreciated.
    $endgroup$
    – user63373
    Mar 10 at 21:19










  • $begingroup$
    @user63373 You're welcome. :)
    $endgroup$
    – Michael E2
    Mar 10 at 22:10















$begingroup$
Thank you very much. This seems to be exactly what is happening. Much appreciated.
$endgroup$
– user63373
Mar 10 at 21:19




$begingroup$
Thank you very much. This seems to be exactly what is happening. Much appreciated.
$endgroup$
– user63373
Mar 10 at 21:19












$begingroup$
@user63373 You're welcome. :)
$endgroup$
– Michael E2
Mar 10 at 22:10




$begingroup$
@user63373 You're welcome. :)
$endgroup$
– Michael E2
Mar 10 at 22:10










user63373 is a new contributor. Be nice, and check out our Code of Conduct.









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user63373 is a new contributor. Be nice, and check out our Code of Conduct.












user63373 is a new contributor. Be nice, and check out our Code of Conduct.











user63373 is a new contributor. Be nice, and check out our Code of Conduct.














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Lowndes Grove History Architecture References Navigation menu32°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661132°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661178002500"National Register Information System"Historic houses of South Carolina"Lowndes Grove""+32° 48' 6.00", −79° 57' 58.00""Lowndes Grove, Charleston County (260 St. Margaret St., Charleston)""Lowndes Grove"The Charleston ExpositionIt Happened in South Carolina"Lowndes Grove (House), Saint Margaret Street & Sixth Avenue, Charleston, Charleston County, SC(Photographs)"Plantations of the Carolina Low Countrye

random experiment with two different functions on unit interval Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)Random variable and probability space notionsRandom Walk with EdgesFinding functions where the increase over a random interval is Poisson distributedNumber of days until dayCan an observed event in fact be of zero probability?Unit random processmodels of coins and uniform distributionHow to get the number of successes given $n$ trials , probability $P$ and a random variable $X$Absorbing Markov chain in a computer. Is “almost every” turned into always convergence in computer executions?Stopped random walk is not uniformly integrable