OFFSET
0,83
COMMENTS
Number of partitions of n into distinct centered pentagonal numbers (A005891).
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..20000 (first 1001 terms from G. C. Greubel)
Eric Weisstein's World of Mathematics, Centered Pentagonal Number
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