OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
FORMULA
G.f.: (1/(1 - x))*Sum_{k>=1} x^(k^4)/(1 - x^(k^4)). - Ilya Gutkovskiy, Feb 11 2017
a(n) ~ zeta(4)*n = Pi^4*n/90. - Vaclav Kotesovec, Oct 12 2019
MATHEMATICA
Table[Sum[Floor[n/k^4], {k, 1, n}], {n, 1, 100}] (* Vaclav Kotesovec, Oct 12 2019 *)
PROG
(PARI) a(n) = sum(k=1, n, n\k^4); \\ Michel Marcus, Feb 11 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved