%I #4 Jun 13 2017 12:50:38
%S 7,8,9,11,13,15,35,59,75
%N Numbers n such that 2^(2*n-13)-13 is prime.
%e 2^(2*11-13)-13=499, 2^(2*13-13)-13=8179, 2^(2*15-13)-13=131059, ...
%t q=13;For[i=q,i<=q,a={};Do[x=2^(2*n-i)-i;If[PrimeQ[x],AppendTo[a,n]],{n,10^2}];Print["2^(2*n-",i,")-",i," ",a];i=i+2]
%o (PARI) is(n)=isprime(2^(2*n-13)-13) \\ _Charles R Greathouse IV_, Jun 13 2017
%K nonn,easy
%O 1,1
%A _Vladimir Joseph Stephan Orlovsky_, May 13 2008