A186687 Primes of the form k*6^m - 1, where k is a Mersenne prime (A000668) and m >= 0.

2, 17, 41, 107, 251, 647, 761, 1511, 23327, 27431, 139967, 3145721, 30233087, 35551871, 6530347007, 39182082047, 91424858111, 146766805631, 6847552083566591, 153558654482644991, 246511875008397311, 14215144014964850687

Offset: 1

Author

Gilbert Mozzo, Feb 25 2011

Keywords

• nonn

Comments

Twin of A185167.

Examples

			(2^1279-1)*6^1047-1 is prime.
		

Crossrefs

Cf. A186104, A186105, A185069, A185167.

Programs

Magma

[n: n in [0..3000] | IsPrime((2^1279-1)*6^n-1)];

Mathematica

Union[Flatten[Table[Select[p*6^Range[0, 30] - 1, # < 10^20 && PrimeQ[#] &], {p, {3, 7, 31, 127, 8191, 131071, 524287, 2147483647, 2305843009213693951}}]]]