OFFSET
0,2
FORMULA
a(n) ~ QPochhammer[-1, 1/4] * 2^(2*n-1) / sqrt(Pi*n).
MATHEMATICA
Table[Sum[PartitionsQ[n-k]*Binomial[2*k, k], {k, 0, n}], {n, 0, 25}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, May 19 2018
STATUS
approved
