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