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A181979 Numbers n such that (29^n - 1)/28 is prime. 1
5, 151, 3719, 49211, 77237 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..5.

H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.

H. Lifchitz, Mersenne and Fermat primes field

Index to primes in various ranges, form ((k+1)^n-1)/k

MATHEMATICA

Select[Prime[Range[100000]], PrimeQ[(29^#-1)/28]&]

PROG

(PARI) isok(n) = isprime((29^n-1)/28); \\ Michel Marcus, Mar 13 2016

CROSSREFS

Sequence in context: A096065 A041431 A107691 * A258486 A082623 A332115

Adjacent sequences:  A181976 A181977 A181978 * A181980 A181981 A181982

KEYWORD

hard,more,nonn

AUTHOR

Robert Price, Apr 04 2012

STATUS

approved

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Last modified February 27 04:40 EST 2021. Contains 341649 sequences. (Running on oeis4.)