OFFSET
0,13
COMMENTS
Number of partitions of n into distinct odd prime powers (1 excluded).
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Eric Weisstein's World of Mathematics, Prime Power
FORMULA
G.f.: Product_{k>=1} (1 + floor(1/omega(2*k+1))*x^(2*k+1)).
EXAMPLE
a(16) = 3 because we have [13, 3], [11, 5], [9, 7].
MATHEMATICA
nmax = 78; CoefficientList[Series[Product[1 + Floor[1/PrimeNu[2 k + 1]] x^(2 k + 1), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 27 2016
STATUS
approved