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A281083
Expansion of Product_{k>=0} (1 + x^(5*k*(k+1)/2+1)).
6
1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 1, 1
OFFSET
0,83
COMMENTS
Number of partitions of n into distinct centered pentagonal numbers (A005891).
FORMULA
G.f.: Product_{k>=0} (1 + x^(5*k*(k+1)/2+1)).
EXAMPLE
a(82) = 2 because we have [76, 6] and [51, 31].
MATHEMATICA
nmax = 105; CoefficientList[Series[Product[1 + x^(5 k (k + 1)/2 + 1), {k, 0, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Ilya Gutkovskiy, Jan 14 2017
STATUS
approved