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

1,1

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

Table of n, a(n) for n=1..33.

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

Formula

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

Mathematica

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

Prog

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

Crossrefs

Cf. A000668, A171252.

Sequence in context: A129119 A259020 A259021 * A074980 A363172 A059218

Adjacent sequences: A171248 A171249 A171250 * A171252 A171253 A171254

Keyword

nonn

Author

M. F. Hasler, Mar 06 2010

Status

approved