OFFSET
1,1
COMMENTS
All terms are composite: due to Fermat's little theorem, 2^p == 2 (mod p) when p is prime. - M. F. Hasler, May 10 2021
LINKS
Zak Seidov, Table of n, a(n) for n = 1..10000
Wikipedia, Fermat's little theorem.
MAPLE
q:= n-> is(2&^n mod n, odd):
select(q, [$1..1000])[]; # Alois P. Heinz, May 10 2021
MATHEMATICA
Select[Range@532, OddQ@PowerMod[2, #, # ] &]
PROG
(PARI) is(n)=lift(Mod(2, n)^n)%2 \\ Charles R Greathouse IV, May 31 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved