OFFSET
0,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: Product_{k>=1} (1 - x^k)/(1 - 2*x^k + x^(k*(k+1))).
From Vaclav Kotesovec, Sep 27 2018: (Start)
a(n) ~ c * phi^(n/2), where
c = 188.4773924093125890061786423020365148584841831715... if n is even
c = 187.5693962190327254176348797865060646998844995050... if n is odd
phi = A001622 = (1+sqrt(5))/2 is the golden ratio. (End)
MAPLE
a:=series(mul(1/(1-add(x^(j*k), j=1..k)), k=1..100), x=0, 46): seq(coeff(a, x, n), n=0..45); # Paolo P. Lava, Apr 02 2019
MATHEMATICA
nmax = 45; CoefficientList[Series[Product[1/(1 - Sum[x^(j k), {j, 1, k}]), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Sep 27 2018
STATUS
approved