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

Author

M. F. Hasler, Apr 30 2007

Keywords

• nonn

Comments

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

Crossrefs

Cf. A005420, A063670.

Programs

PARI

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