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 A176274 #12 Jun 02 2025 02:50:09 %S A176274 14,26,35,38,56,62,65,74,86,95,98,104,122,134,140,143,146,152,155,158, %T A176274 182,185,194,206,209,215,218,224,245,248,254,260,266,278,296,302,305, %U A176274 314,323,326,335,338,341,344,350,362,365,380,386,392,395,398,407,416,422,434,446 %N A176274 Numbers of the form 3k-1 with greatest prime divisor of the form 3m+1. %C A176274 All numbers of the form 2p, where p==1(mod 3) is prime, are in the sequence. %H A176274 Harvey P. Dale, <a href="/A176274/b176274.txt">Table of n, a(n) for n = 1..1000</a> %t A176274 Select[Range[500],Divisible[#+1,3]&&Divisible[FactorInteger[#] [[-1,1]]-1, 3]&] (* _Harvey P. Dale_, Jul 29 2019 *) %o A176274 (PARI) isok(n) = ((n % 3) == 2) && ((vecmax(factor(n)[,1]) % 3) == 1); \\ _Michel Marcus_, Feb 08 2016 %Y A176274 Cf. A176262, A176258, A176257, A176256, A176255, A002148, A002145, A016813, A004767. %K A176274 nonn %O A176274 1,1 %A A176274 _Vladimir Shevelev_, Apr 14 2010 %E A176274 More terms from _Michel Marcus_, Feb 08 2016