A277634 - OEIS

A277634

a(n) = 2^A000668(n) - 1.

7, 127, 2147483647, 170141183460469231731687303715884105727

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OFFSET

1,1

COMMENTS

The terms of this sequence are sometimes called "Double Mersenne numbers" (cf. A263686).

Agrees with A077586 in the first four terms, but then the two sequences differ for the first time at n = 5, because prime(5) = 11 is not in A000043.

a(5) is too large to include in data section (see A276641).

a(n) = A263686(n) iff a(n) is prime, which is the case iff A000668(n) is in A103901.

Agrees with A263686 at least in the first four terms. - Omar E. Pol, Oct 24 2016

LINKS

FORMULA

PROG

(PARI) forprime(p=1, 11, if(ispseudoprime(2^p-1), print1(2^(2^p-1)-1, ", ")))

CROSSREFS

KEYWORD

nonn,bref

AUTHOR

STATUS

approved