OFFSET
0,4
FORMULA
a(n) = [x^(n^2)] (Sum_{k>=0} x^(k^3))^n.
EXAMPLE
a(3) = 6 because we have [8, 1, 0], [8, 0, 1], [1, 8, 0], [1, 0, 8], [0, 8, 1] and [0, 1, 8].
MAPLE
f:= n -> coeff(add(x^(k^3), k=0..floor(n^(2/3)))^n, x, n^2):
map(f, [$0..30]); # Robert Israel, Jan 29 2018
MATHEMATICA
Table[SeriesCoefficient[Sum[x^k^3, {k, 0, Floor[n^(2/3) + 1]}]^n, {x, 0, n^2}], {n, 0, 25}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 29 2018
STATUS
approved