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A180629
Numbers k such that 8*k! - 1 is prime.
6
0, 1, 3, 4, 8, 33, 121, 177, 190, 276, 473, 484, 924, 937, 1722, 2626, 4077, 4464, 6166
OFFSET
1,3
COMMENTS
Tested to 4700. - Robert G. Wilson v, Sep 27 2010
Tested to 5127. - Jinyuan Wang, Feb 03 2020
Tested to 12000. - Michael S. Branicky, Jul 11 2024
MATHEMATICA
fQ[n_] := PrimeQ[8 n! - 1]; k = 0; lst = {}; While[k < 1501, If[ fQ@k, AppendTo[lst, k]; Print@k]; k++ ]; lst
PROG
(PARI) is(k) = ispseudoprime(8*k!-1); \\ Jinyuan Wang, Feb 03 2020
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Sep 13 2010
EXTENSIONS
a(15)-a(18) from Robert G. Wilson v, Sep 27 2010
a(19) from Michael S. Branicky, May 27 2023
STATUS
approved