|
|
A367256
|
|
a(n) = Sum_{k=0..n} binomial(n, k) * binomial(n - 1, k - 1) * n^(n - k).
|
|
2
|
|
|
1, 1, 5, 46, 593, 9726, 192637, 4457580, 117769409, 3492894070, 114790042901, 4137157889316, 162154385331985, 6863637142316332, 311905306734621069, 15140756439172826776, 781693659313991730945, 42759819036520142319270, 2469943332976774829606821
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
FORMULA
|
a(n) = Sum_{k=0..n} A367267(n, k) * n^(n - k).
a(n) = n*n^(n - 1)*hypergeom([1 - n, 1 - n], [2], 1/n) for n > 0.
a(n) ~ exp(2*sqrt(n) - 1) * n^(n - 3/4) / (2*sqrt(Pi)). - Vaclav Kotesovec, Nov 11 2023
|
|
MAPLE
|
a := n -> if n= 0 then 1 else n*n^(n - 1)*hypergeom([1 - n, 1 - n], [2], 1/n) fi:
seq(simplify(a(n)), n = 0..19);
|
|
MATHEMATICA
|
A367256[n_] := If[n == 0, 1, n*n^(n-1)*Hypergeometric2F1[1-n, 1-n, 2, 1/n]];
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|