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 A269453 #32 Apr 01 2016 11:39:54 %S A269453 12,20,30,44,33,92,110,116,69,174,164,230,212,246,290,318,332,356,410, %T A269453 253,452,249,530,534,524,638,678,692,716,830,393,902,764,890,932,956, %U A269453 1038,1166,1130,537,1004,573,1334,1124,1310,1172,1398,717,753,1436,1730,913,1886,1686,1790 %N A269453 The order of 2 mod m when m is the product of two distinct safe primes. %C A269453 The smallest positive integer k for which 2^k == 1 (mod m) where m = p*q with p, q distinct safe primes. %F A269453 a(n) is the order of 2 modulo A157352(n). - _Wolfdieter Lang_, Mar 31 2016 %t A269453 MultiplicativeOrder[2, #] & /@ Select[Select[Range@ 4200, PrimeNu@ # == 2 &], Times @@ Map[If[PrimeQ[(# - 1)/2], #, 0] &, Map[First, FactorInteger@ #]] == # &] (* _Michael De Vlieger_, Feb 28 2016 *) %Y A269453 Cf. A002326, A157352, A269452. %K A269453 nonn %O A269453 1,1 %A A269453 _Marina Ibrishimova_, Feb 27 2016 %E A269453 More terms from _Michael De Vlieger_, Feb 28 2016