Hermann-SW/a11.gp

Last active January 10, 2026 14:50

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Script to verify a(11) for oeis sequence A392244

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a11.gp

	a(n)=parsum(k=1, 10^n, isprime(k^2+(k+1)^2));
	default(threadsizemax,100*10^6); \\ default 8MB was too small
	#
	print(a(11));

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Hermann-SW commented Jan 10, 2026

Started with nohup numactl -C 0-191 gp -q < a11.gp, expected runtime <10h real time

Wow, I expected <10h, but not that much under, nice:

hermann@x3950-X6:~$ sed "s/\xd/\n/g" nohup.out
   timer = 1 (on)
  *** isprime: Warning: increasing stack size to 16000000.
  *** isprime: Warning: increasing stack size to 32000000.
  *** isprime: Warning: increasing stack size to 64000000.
5573589175
cpu time = 1110h, 34min, 16,003 ms, real time = 5h, 47min, 8,619 ms.
hermann@x3950-X6:~$

Confirms a(11) value of A392244 computed otherwise before:
https://gist.github.com/Hermann-SW/94241e719dd3518a3276d804b627319d?permalink_comment_id=5929893#gistcomment-5929893
That code did take 14:28h real time, but only because the parallel workload was distributed too unequally.

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