%I #6 Apr 30 2019 16:03:50
%S 7,37,67,73,89,179,191,373,479,521,601,613,619,653,661,673,701,719,
%T 727,769,773,853,881,907,919,1553,1571,1693,1709,1747,1831,2003,2111,
%U 2137,2309,2347,2351,2543,2593,2707,2719,2837,3023,3361,3583,3613,3673,3727
%N p=prime is substring of 2^p-1.
%C n such that p=prime(n) is substring of 2^p-1 in A086109.
%e a(2)=37 because prime=37 is substring of 2^37-1=137438953471.
%t Select[Prime[Range[600]],SequenceCount[IntegerDigits[2^#-1],IntegerDigits[ #]]>0&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 30 2019 *)
%Y Cf. A086109.
%K easy,nonn,base
%O 0,1
%A _Zak Seidov_, Jul 10 2003