OFFSET
0,10
COMMENTS
Number of compositions (ordered partitions) of n into odd squares (A016754).
LINKS
FORMULA
G.f.: 1/(1 - Sum_{k>=0} x^((2*k+1)^2)).
EXAMPLE
a(12) = 5 because we have [9, 1, 1, 1], [1, 9, 1, 1], [1, 1, 9, 1], [1, 1, 1, 9] and [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1].
MATHEMATICA
nmax = 63; CoefficientList[Series[1/(1 - Sum[x^(2 k + 1)^2, {k, 0, nmax}]), {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 09 2017
STATUS
approved