|
|
A265836
|
|
Expansion of Product_{k>=1} 1/(1 - k*(k+1)*x^k).
|
|
3
|
|
|
1, 2, 10, 32, 120, 342, 1206, 3320, 10604, 29578, 88342, 239400, 702020, 1863654, 5262650, 13948824, 38427192, 100244162, 272822282, 703972024, 1883948848, 4839944150, 12779850278, 32548367784, 85335644100, 215826029018, 560407835934, 1412632075328
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
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):
|
|
MATHEMATICA
|
nmax = 40; CoefficientList[Series[Product[1/(1 - k*(k+1)*x^k), {k, 1, nmax}], {x, 0, nmax}], x]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|