OFFSET
0,1
LINKS
Max Alekseyev, Table of n, a(n) for n = 0..387
EXAMPLE
a(4)=4 because 7^4+1 has divisors {1, 2, 1201, 2402}.
MAPLE
a:=n->numtheory[tau](7^n+1):
seq(a(n), n=0..100);
MATHEMATICA
DivisorSigma[0, 7^Range[0, 62] + 1] (* Paul F. Marrero Romero, Oct 16 2023 *)
PROG
(PARI) a(n) = numdiv(7^n+1);
CROSSREFS
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 15 2023
STATUS
approved