OFFSET
0,36
COMMENTS
Number of partitions of n into distinct tetrahedral numbers (A000292).
LINKS
Eric Weisstein's World of Mathematics, Tetrahedral Number
FORMULA
G.f.: Product_{k>=1} (1 + x^(k*(k+1)*(k+2)/6)).
EXAMPLE
a(35) = 2 because we have [35] and [20, 10, 4, 1].
MATHEMATICA
nmax=120; CoefficientList[Series[Product[1 + x^(k (k + 1) (k + 2)/6), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 09 2016
STATUS
approved