%I #19 Sep 15 2022 06:30:03
%S 2,7,37,1297
%N Primes of the form 6^k + 1.
%C No other terms for k < 3000. - _T. D. Noe_, Apr 25 2012
%C Apart from the first term, the exponents must be powers of two. Like Fermat primes, there are probably only finitely many terms. No more terms for k < 2^28 = 268435456. - _Charles R Greathouse IV_, Jul 16 2012
%H Wilfrid Keller, <a href="http://www.prothsearch.com/GFN06.html">Prime factors of generalized Fermat numbers F_m(6) and complete factoring status</a>
%t Select[Table[6^n + 1, {n, 0, 100}], PrimeQ] (* _T. D. Noe_, Apr 25 2012 *)
%o (PFGW) ABC2 6^(2^$a)+1
%o a: from 0 to 18
%o // _Charles R Greathouse IV_, Jul 16 2012
%Y Cf. A057735, A182330.
%K nonn
%O 1,1
%A _Alex Ratushnyak_, Apr 25 2012