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 A231918 #14 Apr 03 2023 10:36:13
%S A231918 50411,116411,495611,705119,730451,816839,1074851,1851851,2263619,
%T A231918 2827679,3355991,3979511,4513979,5108639,5347211,5654651,6098759,
%U A231918 6673391,7153199,7862579,8497451,8754131,10763939,10852739,11649611,12523499,12561551,12694991
%N A231918 Primes p such that (2*p + 1)*(8*p + 1)*(18*p + 1) divides 2^p - 1.
%H A231918 Chris Caldwell, The Prime Glossary, <a href="https://t5k.org/glossary/xpage/MersenneNumber.html">Mersenne number</a>
%H A231918 C. K. Caldwell, "Top Twenty" page, <a href="https://t5k.org/top20/page.php?id=49">Mersenne cofactor</a>
%t A231918 lst = {}; Do[If[PrimeQ[p] && PowerMod[2, p, 288*p^3 + 196*p^2 + 28*p + 1] == 1, AppendTo[lst, p]], {p, 12694991}]; lst
%Y A231918 Subsequence of A231916.
%Y A231918 Cf. A001348, A231917.
%K A231918 nonn,less
%O A231918 1,1
%A A231918 _Arkadiusz Wesolowski_, Nov 15 2013