OFFSET
0,1
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..10000
FORMULA
a(n) ~ 3^(1/4) * n^(3/4) * exp(Pi*sqrt(n/3)) / Pi^3.
MATHEMATICA
max=50; col=3; s1=Series[Product[(1+x^(n-k)*y^k), {n, 1, max+2}, {k, 0, n}], {y, 0, col}]//Normal; s2=Series[s1, {x, 0, max+1}]; a[n_]:=SeriesCoefficient[s2, {x, 0, n}, {y, 0, col}]; Table[a[n], {n, 0, max}] (* after Jean-François Alcover *)
nmax = 50; CoefficientList[Series[((2 + x - x^2 - x^3 - x^4 + x^5) / ((1 - x)*(1 - x^2)*(1 - x^3))) * Product[1 + x^k, {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Feb 02 2016
STATUS
approved