OFFSET
0
COMMENTS
The difference between the number of partitions of n into an even number of distinct square pyramidal numbers and the number of partitions of n into an odd number of distinct square pyramidal numbers.
LINKS
Eric Weisstein's World of Mathematics, Square Pyramidal Number
FORMULA
G.f.: Product_{k>=1} (1 - x^A000330(k)).
MATHEMATICA
nmax = 104; CoefficientList[Series[Product[1 - x^(k (k + 1) (2 k + 1)/6), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Jan 15 2018
STATUS
approved