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A180628 Numbers n such that 7*n!-1 is a prime. 0
2, 3, 4, 5, 6, 7, 8, 12, 23, 25, 31, 57, 74, 86, 140, 240, 310, 703, 713, 796, 1028, 1102 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..22.

Index entries for sequences related to numbers of primes of the form k*n!+-1

MATHEMATICA

fQ[n_] := PrimeQ[7 n! - 1]; k = 0; lst = {}; While[k < 1501, If[ fQ@k, AppendTo[lst, k]; Print@k]; k++ ]; lst

CROSSREFS

Sequence in context: A033087 A084589 A271831 * A165306 A254116 A254115

Adjacent sequences:  A180625 A180626 A180627 * A180629 A180630 A180631

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 13 2010

STATUS

approved

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Last modified March 20 23:22 EDT 2019. Contains 321354 sequences. (Running on oeis4.)