A046706 - OEIS

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A046706

a(n) = (1/2)*(n+1)!*Sum_{k=0..floor(n/2)} n^(2k+1)/(2k+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

Andrew Howroyd, Table of n, a(n) for n = 0..200

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

Sequence in context: A218127 A322647 A243106 * A337867 A374228 A116348

Adjacent sequences: A046703 A046704 A046705 * A046707 A046708 A046709

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

STATUS

approved