OFFSET
0,7
LINKS
FORMULA
G.f.: Product_{k>=2} (1 + x^(2*k) / (1 - x^k)).
a(n) ~ exp(2*Pi*sqrt(n)/3) * Pi / (18*sqrt(2)*n^(3/2)). - Vaclav Kotesovec, Dec 09 2020
EXAMPLE
a(12) = 6 because we have [6, 6], [4, 4, 4], [4, 4, 2, 2], [3, 3, 3, 3], [3, 3, 2, 2, 2] and [2, 2, 2, 2, 2, 2].
MATHEMATICA
nmax = 63; CoefficientList[Series[Product[1 + x^(2 k)/(1 - x^k), {k, 2, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 27 2020
STATUS
approved