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A298600
Expansion of Product_{k>=2} 1/(1 + x^(k^2)).
1
1, 0, 0, 0, -1, 0, 0, 0, 1, -1, 0, 0, -1, 1, 0, 0, 0, -1, 1, 0, 0, 1, -1, 0, 0, -1, 1, -1, 0, 1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, 0, -2, 2, -1, 1, 2, -2, 1, -1, -2, 3, -2, 1, 2, -3, 2, -1, -1, 2, -3, 1, 1, -2, 3, 0, 0, 2, -3, 1, -1, -2, 3, -1, -2, 2
OFFSET
0,50
COMMENTS
The difference between the number of partitions of n into an even number of squares > 1 and the number of partitions of n into an odd number of squares > 1.
FORMULA
G.f.: Product_{k>=2} 1/(1 + x^(k^2)).
MATHEMATICA
nmax = 82; CoefficientList[Series[Product[1/(1 + x^k^2), {k, 2, Floor[Sqrt[nmax]] + 1}], {x, 0, nmax}], x]
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Jan 22 2018
STATUS
approved