|
|
A351796
|
|
a(n) = n! * Sum_{k=0..n} (-k * (n-k))^k/k!.
|
|
1
|
|
|
1, 1, 0, 6, 36, -1240, 36810, -743568, -4441640, 2126086272, -201265464330, 13670088101120, -512174277963612, -50655591400627200, 16935777106057251442, -2936123018591228282880, 368896773292405165345200, -22278163772113766968557568
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,4
|
|
LINKS
|
|
|
MATHEMATICA
|
a[n_] := n!*(1 + Sum[(-k*(n - k))^k/k!, {k, 1, n}]); Array[a, 18, 0] (* Amiram Eldar, Feb 19 2022 *)
|
|
PROG
|
(PARI) a(n) = n!*sum(k=0, n, (-k*(n-k))^k/k!);
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|