OFFSET
0,4
COMMENTS
Sum of products of terms in all partitions of n into distinct odd parts.
FORMULA
G.f.: Product_{k>=0} (1 + (2*k + 1)*x^(2*k+1)).
EXAMPLE
a(10) = 30 because we have [9, 1], [7, 3], 9*1 = 9, 7*3 = 21 and 9 + 21 = 30.
MATHEMATICA
nmax = 48; CoefficientList[Series[Product[1 + (2 k + 1) x^(2 k + 1), {k, 0, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 09 2017
STATUS
approved