OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
MAPLE
select(n->gcd(factorial(n)-1, 2^n+1)>1, [$1..1230]); # Muniru A Asiru, Oct 16 2018
MATHEMATICA
Select[Range[2500], GCD[#! - 1, 2^# + 1] > 1 &] (* G. C. Greubel, Oct 15 2018 *)
PROG
(PARI) isok(n) = gcd(n!-1, 2^n+1) > 1; \\ Michel Marcus, Oct 16 2018
(GAP) Filtered([1..1230], n->Gcd(Factorial(n)-1, 2^n+1)>1); # Muniru A Asiru, Oct 16 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Mar 10 2002
STATUS
approved