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 A110025 #7 Apr 03 2023 10:36:11 %S A110025 509,1229,1409,2131,2311,2699,3539,6211,6449,7411,10321,10589,11549, %T A110025 11909,12119,17159,18121,19709,19889,22349,22531,23011,24391,26189, %U A110025 27479,29671,30389,31771,35311,41491,43649,46411,54601,55229,56311 %N A110025 Smallest primes starting a complete three iterations Cunningham chain of the first or second kind. %C A110025 Terms computed by Gilles Sadowski. %H A110025 Chris Caldwell's Prime Glossary, <a href="https://t5k.org/glossary/page.php?sort=CunninghamChain">Cunningham chains</a>. %F A110025 Union of A059763 and A110024. [_R. J. Mathar_, May 08 2009] %e A110025 1409 is here because, through the operator <2p+1> for chains of the first kind, 1409 -> 2819 -> 5639 -> 11279 and the chain ends here. %e A110025 2131 is here because, through the operator <2p-1> for chains of the second kind, 2131 -> 4261 -> 8521 -> 17041 and the chain ends here. %Y A110025 Cf. A023272, A023302, A023330, A005384, A005385, A059452, A059455, A007700. %Y A110025 Cf. A059759, A059760, A059761, A059762, A059763, A059764, A059765, A038397, A104349, A091314, A069362, A016093, A014937, A057326. %K A110025 easy,nonn %O A110025 1,1 %A A110025 _Alexandre Wajnberg_, Sep 03 2005 %E A110025 Edited by _R. J. Mathar_, May 08 2009