OFFSET
0,6
LINKS
Eric Weisstein's World of Mathematics, Tetrahedral Number
EXAMPLE
a(5) = 2 because fifth tetrahedral number is 35 and we have [35] and [20, 10, 4, 1].
MATHEMATICA
Table[SeriesCoefficient[Product[1 + x^(k (k + 1) (k + 2)/6), {k, 1, n}], {x, 0, n (n + 1) (n + 2)/6}], {n, 0, 53}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 27 2018
STATUS
approved