This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A297415 #12 Jul 17 2021 23:36:07
%S A297415 25,36,52,92,124,306,361,630,656,1648,1780,2508,3300,3540,5728,6260,
%T A297415 6450,7500,10820,12656,14076,14132,18836,20960,23456,24272,35280,43136
%N A297415 Numbers k such that A019320(k) is in A217465.
%o A297415 (PARI) is_A297415(n) = my(m=polcyclo(n, 2)); (m>1) && Mod(2, m*(m+1))^m==2 && !ispseudoprime(m);
%Y A297415 Cf. A019320, A217465, A297412.
%Y A297415 Set difference of A297414 and ({1} U A072226).
%K A297415 nonn,more
%O A297415 1,1
%A A297415 _Max Alekseyev_, Dec 29 2017