A128997 indices k such that A063670(k) differs from A005420(k).

11, 12, 15, 20, 21, 22, 23, 24, 25, 28, 29, 30, 33, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96

Offset

1,1

Comments

Primes in this sequence are those for which A005420(n) < 2^n-1, i.e. 2^n-1 is not prime.

Links

Table of n, a(n) for n=1..69.

Prog

(PARI) t=1; vector(100, i, until( A063670(t++) != A005420(t), ); t)

Crossrefs

Cf. A005420, A063670.

Sequence in context: A274566 A349153 A213309 * A189836 A292683 A139138

Adjacent sequences: A128994 A128995 A128996 * A128998 A128999 A129000

Keyword

nonn

Author

M. F. Hasler, Apr 30 2007

Status

approved