OFFSET
1,1
COMMENTS
Numbers k such that (k!-m)/m is prime:
for m=1 see A002982
for m=2 prime or pseudoprime see A082671
for m=3 see A139056
for m=4 see A139199
for m=5 see A139200
for m=6 see A139201
for m=7 see A139202
for m=8 see A139203
for m=9 see A139204
for m=10 see A139205
a(17) > 2000 - Ray G. Opao, Sep 30 2008
a(21) > 25000 - Robert Price, Sep 25 2016
MATHEMATICA
a = {}; Do[If[PrimeQ[(n! - 4)/4], Print[a]; AppendTo[a, n]], {n, 1, 184}]; a (*Artur Jasinski*)
PROG
(PARI) is(n)=n>3 && isprime(n!/4-1) \\ Charles R Greathouse IV, Apr 29 2015
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Artur Jasinski, Apr 11 2008
EXTENSIONS
a(15)-a(16) from Ray G. Opao, Sep 30 2008
a(17) from Serge Batalov, Feb 18 2015
a(18)-a(20) from Robert Price, Sep 25 2016
STATUS
approved