A200655 a(n)= least number k > a(n-1) such that k*(2^p-1)*(k*(2^p-1)+1)-1 is prime, where p = A000043(n) = Mersenne exponents.

1, 3, 5, 7, 8, 19, 20, 23, 96, 190, 312, 400, 434, 852, 980, 1063, 1208, 3960, 5464, 6694, 7178, 13118, 13680, 18803, 27445, 28541, 42031, 73209, 83873

Offset: 1

Author

Pierre CAMI, Nov 21 2011

Keywords

• nonn

Comments

a(n) is not so far from p

All certified primes using PFGW64 from primeform group

Crossrefs

Cf. A000043, A121370