login
A139203
Numbers k such that (k!-8)/8 is prime.
3
4, 6, 8, 10, 11, 16, 19, 47, 66, 183, 376, 507, 1081, 1204, 12111, 23181
OFFSET
1,1
COMMENTS
a(17) > 25000. - Robert Price, Oct 08 2016
MAPLE
a:=proc(n) if isprime((1/8)*factorial(n)-1)=true then n else end if end proc: seq(a(n), n=4..550); # Emeric Deutsch, May 07 2008
MATHEMATICA
a = {}; Do[If[PrimeQ[(n! - 8)/8], Print[a]; AppendTo[a, n]], {n, 1, 300}]; a
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Artur Jasinski, Apr 11 2008
EXTENSIONS
2 more terms from Emeric Deutsch, May 07 2008
More terms from Serge Batalov, Feb 18 2015
a(15)-a(16) from Robert Price, Oct 08 2016
STATUS
approved