OFFSET
0,5
COMMENTS
a(n) = A264391(n,0).
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..10000
FORMULA
G.f.: Product_{i>=1}(1-x^(h(i)))/(1-x^i), where h(i) = i^3.
a(n) ~ exp(Pi*sqrt(2*n/3) - 2^(1/6) * Gamma(1/3) * Zeta(4/3) * n^(1/6) / (3^(5/6) * Pi^(1/3))) * Pi / (6^(1/4) * n^(3/4)). - Vaclav Kotesovec, Dec 30 2016
EXAMPLE
a(7) = 4 because we have [7], [5,2], [4,3], and [3,2,2].
MAPLE
h := proc (i) options operator, arrow; i^3 end proc: g := product((1-x^h(i))/(1-x^i), i = 1 .. 150): gser := series(g, x = 0, 65): seq(coeff(gser, x, n), n = 0 .. 60);
MATHEMATICA
nmax=100; CoefficientList[Series[Product[(1-x^(k^3))/(1-x^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Dec 30 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Nov 13 2015
STATUS
approved