A240105 Integers m such that 2*m^k + 1, for k = 2..7, are prime.

1, 3490575, 83972646, 414180489, 476072025, 1881147720, 3020243916, 3188924769, 3285167214, 3543143220, 6593858205, 8239349955, 10914074124, 14102235060, 15455042889, 16196415300, 16588528539, 16636093485, 17688635511, 17929182270, 18997337436, 19290317670, 19347263739

Offset: 1

Author

Zak Seidov, Apr 01 2014

Keywords

• nonn

Comments

First m>1 such that 2*m^k+1, for k=2..8, are prime, is a(3) = 83972646.

Subsequence of A240099: a(2) = 3490575 = A240099(4), a(3) = 83972646 = A240099(22).

Crossrefs

Cf. A089001, A168550, A239874, A239925, A240099.

Extensions

More terms from Jinyuan Wang, Jun 12 2025