|
|
A046706
|
|
a(n) = (1/2)*(n+1)!*Sum_{k=0..floor(n/2)} n^(2k+1)/(2k+1)!.
|
|
1
|
|
|
0, 1, 10, 90, 1392, 18675, 409104, 7411348, 209085952, 4788571365, 164757984000, 4571341663086, 185247857018880, 6045063784869655, 281596888593405952, 10574853536725785000, 556202715633735696384, 23639922913364842592457
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
MATHEMATICA
|
Table[(n+1)!/2 Sum[n^(2k+1)/(2k+1)!, {k, 0, Floor[n/2]}], {n, 0, 20}] (* Harvey P. Dale, Mar 05 2013 *)
|
|
PROG
|
(PARI) a(n) = {(n+1)!*sum(k=0, n\2, n^(2*k+1)/(2*k+1)!)/2} \\ Andrew Howroyd, Mar 07 2020
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|