OFFSET
0,2
FORMULA
a(n) ~ c * 4^n / (sqrt(Pi) * n^(3/2)), where c = QPochhammer[-1, 1/4] / (2*QPochhammer[1/4, 1/4]) = 1.96926035366826943194719369696726567...
MATHEMATICA
Table[Sum[Sum[PartitionsP[k-j] * PartitionsQ[j], {j, 0, k}] * CatalanNumber[n-k], {k, 0, n}], {n, 0, 50}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Sep 20 2017
STATUS
approved