OFFSET
1,1
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..388
EXAMPLE
a(5)=8 because 7^5-1 has divisors {1, 2, 3, 6, 2801, 5602, 8403, 168061}.
MAPLE
a:=n->numtheory[tau](7^n-1):
seq(a(n), n=1..100);
MATHEMATICA
DivisorSigma[0, 7^Range[100]-1]
PROG
(PARI) a(n) = numdiv(7^n-1);
CROSSREFS
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 14 2023
STATUS
approved