OFFSET
0,6
COMMENTS
Column 0 of A117274.
FORMULA
G.f.: (1+x^2)*product((1+x^(2k))/(1-x^(2k-1)), k=2..infinity).
a(n) ~ exp(sqrt(n/2)*Pi) * Pi / (2^(17/4) * n^(5/4)). - Vaclav Kotesovec, Mar 07 2016
EXAMPLE
a(8)=4 because we have [8],[6,2],[5,3] and [3,3,2].
MAPLE
g:=(1+x^2)*product((1+x^(2*k))/(1-x^(2*k-1)), k=2..53): gser:=series(g, x=0, 62): seq(coeff(gser, x, n), n=0..58);
MATHEMATICA
nmax = 60; CoefficientList[Series[(1-x) * Product[(1+x^(2*k))/(1-x^(2*k-1)), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Mar 07 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Mar 06 2006
STATUS
approved