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A189992 Numbers n such that 2^n'-1 is prime, where n' is the arithmetic derivative of n. 0
6, 10, 22, 30, 34, 58, 66, 118, 618, 730, 874, 1353, 2554, 2937, 7874, 7954, 8842, 11922, 12430, 15442, 17186, 26034, 115690, 166774, 170134, 221002, 264094, 368599, 1419045, 1443118, 1582026, 1583759, 1587721, 1829929, 1934249, 2053321, 2160359, 2207345 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

These numbers are the anti-derivatives of the Mersenne primes A000043. The prime 86243 has 11 anti-derivatives! - T. D. Noe, May 04 2011

LINKS

Table of n, a(n) for n=1..38.

EXAMPLE

6'=5, 2^5-1=31 = prime -> a(1) = 6

MAPLE

last:=120: der:=n->n*add(op(2, p)/op(1, p), p=ifactors(n)[2]): seq(`if`(isprime(2^(der(i))- 1)=true, i, NULL), i=2..last);

CROSSREFS

Cf. A000043, A001348, A003415.

Sequence in context: A082419 A102783 A157037 * A255746 A082917 A001172

Adjacent sequences:  A189989 A189990 A189991 * A189993 A189994 A189995

KEYWORD

nonn

AUTHOR

Giorgio Balzarotti, May 03 2011

EXTENSIONS

Extended by T. D. Noe, May 04 2011

STATUS

approved

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Last modified December 6 22:42 EST 2021. Contains 349567 sequences. (Running on oeis4.)