OFFSET
1,1
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..310
EXAMPLE
a(3)=4 because 12^3-1 has divisors {1, 11, 157, 1727}.
MAPLE
a:=n->numtheory[tau](12^n-1):
seq(a(n), n=1..100);
MATHEMATICA
DivisorSigma[0, 12^Range[100]-1]
PROG
(PARI) a(n) = numdiv(12^n-1);
CROSSREFS
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 17 2023
STATUS
approved