A171251 Sums of two (not necessarily distinct) Mersenne primes (A000668).

6, 10, 14, 34, 38, 62, 130, 134, 158, 254, 8194, 8198, 8222, 8318, 16382, 131074, 131078, 131102, 131198, 139262, 262142, 524290, 524294, 524318, 524414, 532478, 655358, 1048574, 2147483650, 2147483654, 2147483678, 2147483774, 2147491838

Offset: 1

Author

M. F. Hasler, Mar 06 2010

Keywords

• nonn

Comments

All terms are even, since all terms of A000668 are odd. This motivates to introduce A171252 = (1/2) * A171251, see there for further information.

Links

• Jonathan Vos Post, Sums of three Mersenne primes, and prime sums of three Mersenne primes, SeqFan list, Mar 5, 2010.

Crossrefs

Cf. A000668, A171252.

Programs

Mathematica

With[{mps=Select[2^Range[50]-1,PrimeQ]},Union[Total/@Tuples[mps,2]]] (* Harvey P. Dale, Aug 11 2012 *)
With[{mps=2^MersennePrimeExponent[Range[10]]-1},Union[Total/@Tuples[mps,2]]] (* Harvey P. Dale, Mar 20 2025 *)

PARI

concat(vector(#A000668,i,vector(i,j,A000668[i]+A000668[j]))) /* having defined A000668 as vector with initial terms of A000668 */

Formula

A171251(n) = 2*A171252(n) = A000668(i) + A000668(j) where n = i*(i-1)/2+j.