%I #9 Jul 11 2021 14:32:40
%S 4,10,16,28,36,50,56,76,82,106,116,120,122,134,144,162,172,176,188,
%T 190,204,216,218,232,236,244,248,254,256,262,274,280,290,296,298,300,
%U 324,334,336,344,352,364,372,396,404,406,414,426,438,452,456,474,476,484
%N Numbers k such that 2^k mod k-1 is odd.
%t Select[ 2Range[250], OddQ[ PowerMod[2, #, #-1]] &] (* _Robert G. Wilson v_, Oct 10 2005 *)
%Y Cf. A112983, A015911.
%K nonn
%O 1,1
%A _Paul Barry_, Oct 08 2005
%E More terms from _Robert G. Wilson v_, Oct 10 2005