OFFSET
1,1
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..310
EXAMPLE
a(3)=1896 because 12^3-1 has divisors {1, 11, 157, 1727}.
MAPLE
a:=n->numtheory[sigma](12^n-1):
seq(a(n), n=1..100);
MATHEMATICA
DivisorSigma[1, 12^Range[30]-1]
CROSSREFS
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 17 2023
STATUS
approved