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

7, 13, 29, 97, 113, 193, 449, 509, 769, 7937, 12289, 114689, 520193, 786433, 7340033, 8388593, 33292289, 33550337, 469762049, 2130706433, 3221225473, 8588886017, 137438691329, 206158430209, 2199023254529, 6597069766657, 562948879679489, 7881299347898369, 9007182074871809

Offset

1,1

Links

Table of n, a(n) for n=1..29.

Formula

For all n >= 1, A335885(a(n)) <= 2.

Prog

(PARI)
A000265(n) = (n>>valuation(n, 2));
isA000668(n) = (isprime(n)&&!bitand(n, 1+n));
isA336117(n) = (isprime(n)&&isA000668(A000265(n-1)));

Crossrefs

Cf. A000265, A000668, A334092, A335874, A335885, A336116.

Sequence in context: A182624 A096333 A133325 * A283709 A063583 A350072

Adjacent sequences: A336114 A336115 A336116 * A336118 A336119 A336120

Keyword

nonn

Author

Antti Karttunen, Jul 09 2020

Extensions

More terms from Jinyuan Wang, Jul 11 2020

Status

approved