OFFSET
1,1
COMMENTS
a(26) > 12000. - Michael S. Branicky, Jul 07 2024
LINKS
MATHEMATICA
fQ[n_] := PrimeQ[7 n! - 1]; k = 0; lst = {}; While[k < 1501, If[ fQ@k, AppendTo[lst, k]; Print@k]; k++ ]; lst
Select[Range[4000], PrimeQ[7#!-1]&] (* Harvey P. Dale, Apr 22 2024 *)
PROG
(PARI) is(k) = ispseudoprime(7*k!-1); \\ Jinyuan Wang, Feb 03 2020
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Sep 13 2010
EXTENSIONS
a(23) from Jinyuan Wang, Feb 03 2020
a(24)-a(25) from Michael S. Branicky, Apr 25 2023
STATUS
approved