|
|
A367884
|
|
Expansion of e.g.f. 1/(1 + x * log(1-3*x)).
|
|
1
|
|
|
1, 0, 6, 27, 432, 5670, 107892, 2245320, 55380672, 1525511232, 47089609200, 1600308206640, 59508149907456, 2400782506705440, 104471929620067968, 4876509369382166880, 243046385420037166080, 12881279635221755358720, 723372722620484975659008
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
FORMULA
|
a(0) = 1; a(n) = n! * Sum_{k=2..n} 3^(k-1)/(k-1) * a(n-k)/(n-k)!.
a(n) = n! * Sum_{k=0..floor(n/2)} 3^(n-k) * k! * |Stirling1(n-k,k)|/(n-k)!.
|
|
PROG
|
(PARI) a(n) = n!*sum(k=0, n\2, 3^(n-k)*k!*abs(stirling(n-k, k, 1))/(n-k)!);
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|