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A128997 indices k such that A063670(k) differs from A005420(k). 0
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 (list; graph; refs; listen; history; text; internal format)
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: A121978 A274566 A213309 * A189836 A292683 A139138

Adjacent sequences:  A128994 A128995 A128996 * A128998 A128999 A129000

KEYWORD

nonn

AUTHOR

M. F. Hasler, Apr 30 2007

STATUS

approved

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Last modified November 26 03:20 EST 2020. Contains 338632 sequences. (Running on oeis4.)