OFFSET
1,1
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A001157(3*n).
Sum_{k=1..n} a(k) ~ (29*zeta(3)/9) * n^3. - Amiram Eldar, Dec 12 2023
MATHEMATICA
Table[DivisorSigma[2, 3n], {n, 1, 43}] (* Indranil Ghosh, Mar 03 2017 *)
PROG
(PARI) a(n) = sigma(3*n, 2); \\ Indranil Ghosh, Mar 03 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Mar 03 2017
STATUS
approved