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 A292188 #17 Sep 11 2017 14:06:35 %S A292188 8,9,15,21,24,32,39,51,57,64,65,75,85,93,111,115,121,133,183,201,217, %T A292188 265,267,279,303,305,309,321,341,381,415,417,427,445,671,745,771,807, %U A292188 813,843,879,889,1041,1047,1059,1119,1137,1203 %N A292188 Composite numbers m such that all prime divisors p > m of 2^m - 1 are of the form p = 2*k*m + 1. %C A292188 There are no terms of the forms q-1 and 2q with q prime. %C A292188 Are there infinitely many the terms m = 3q with q prime? %e A292188 For 2^15 - 1 = 7*31*151, 30/15 = 2 and 150/15 = 10, so 15 is a term. %e A292188 For 2^16 - 1 = 3*5*17*257, 16/16 = 1 is odd, so 16 is not a term. %Y A292188 Cf. A000040, A000225, A060443. %K A292188 nonn %O A292188 1,1 %A A292188 _Thomas Ordowski_, Sep 11 2017 %E A292188 a(13)-a(48) from _Max Alekseyev_, Sep 11 2017