OFFSET
0,2
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..2000
FORMULA
a(n) ~ c * 6^(n/2), where
c = 79.0418032646837469192452349...... if n is even,
c = 78.4480460169710091436913691...... if n is odd.
MAPLE
b:= proc(n, i) option remember; `if`(n=0 or i=1,
2^n, b(n, i-1)+(1+i)*i*b(n-i, min(n-i, i)))
end:
a:= n-> b(n$2):
seq(a(n), n=0..33); # Alois P. Heinz, Aug 16 2019
MATHEMATICA
nmax = 40; CoefficientList[Series[Product[1/(1 - k*(k+1)*x^k), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Dec 16 2015
STATUS
approved