OFFSET
1,2
EXAMPLE
39 is in the sequence as A000340(39-1) = 3039416364764232180 is divisible by 39. - David A. Corneth, Aug 08 2021
PROG
(PARI) lista(nn) = my(s); for(k=1, nn, s=3*s+k; if(s%k==0, print1(k, ", "))); \\ Jinyuan Wang, Aug 08 2021
(PARI) is(n) = n%2==1 && lift(Mod(3, n)^(n + 1) - Mod(3, n)) == 0 \\ David A. Corneth, Aug 08 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(7)-a(16) from Arkadiusz Wesolowski, Jul 03 2011
More terms from David A. Corneth, Aug 08 2021
STATUS
approved