OFFSET
1,1
COMMENTS
If n=p-1, p prime, then n is in the sequence.
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..230]); # Muniru A Asiru, Oct 16 2018
MATHEMATICA
Select[Range[300], GCD[#!+1, 2^#-1]>1&] (* Harvey P. Dale, Jan 31 2015 *)
PROG
(PARI) isok(n) = gcd(n!+1, 2^n-1) > 1; \\ Michel Marcus, Oct 16 2018
(GAP) Filtered([1..230], n->Gcd(Factorial(n)+1, 2^n-1)>1); # Muniru A Asiru, Oct 16 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Mar 10 2002
STATUS
approved