

A180628


Numbers k such that 7*k!  1 is prime.


8



2, 3, 4, 5, 6, 7, 8, 12, 23, 25, 31, 57, 74, 86, 140, 240, 310, 703, 713, 796, 1028, 1102, 1924
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OFFSET

1,1


COMMENTS

a(24) > 2589.  Jinyuan Wang, Feb 03 2020


LINKS

Table of n, a(n) for n=1..23.
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


PROG

(PARI) is(k) = ispseudoprime(7*k!1); \\ Jinyuan Wang, Feb 03 2020


CROSSREFS

Cf. A002982, A076133, A076134, A099350, A099351, A180627, A180629, A180630, A180631.
Sequence in context: A033087 A084589 A271831 * A165306 A254116 A254115
Adjacent sequences: A180625 A180626 A180627 * A180629 A180630 A180631


KEYWORD

nonn,more


AUTHOR

Robert G. Wilson v, Sep 13 2010


EXTENSIONS

a(23) from Jinyuan Wang, Feb 03 2020


STATUS

approved



