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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A336117 Primes of the form q*2^h + 1, where q is a Mersenne prime.

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%I A336117 #16 Jul 11 2020 10:19:38
%S A336117 7,13,29,97,113,193,449,509,769,7937,12289,114689,520193,786433,
%T A336117 7340033,8388593,33292289,33550337,469762049,2130706433,3221225473,
%U A336117 8588886017,137438691329,206158430209,2199023254529,6597069766657,562948879679489,7881299347898369,9007182074871809
%N A336117 Primes of the form q*2^h + 1, where q is a Mersenne prime.
%F A336117 For all n >= 1, A335885(a(n)) <= 2.
%o A336117 (PARI)
%o A336117 A000265(n) = (n>>valuation(n,2));
%o A336117 isA000668(n) = (isprime(n)&&!bitand(n,1+n));
%o A336117 isA336117(n) = (isprime(n)&&isA000668(A000265(n-1)));
%Y A336117 Cf. A000265, A000668, A334092, A335874, A335885, A336116.
%K A336117 nonn
%O A336117 1,1
%A A336117 _Antti Karttunen_, Jul 09 2020
%E A336117 More terms from _Jinyuan Wang_, Jul 11 2020