OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..180
FORMULA
Recurrence: a(n) = (n+1)*(n^2-n+1)*a(n-1)-(n-1)^3*a(n-2).
a(n) ~ 2.12970254898330641813452361... * (n!)^3 = A271574 * (n!)^3.
a(n) = n^3 * a(n-1) + 1. - Seiichi Manyama, May 02 2021
MATHEMATICA
Table[Sum[(n!/k!)^3, {k, 0, n}], {n, 0, 20}]
PROG
(PARI) a(n) = sum(k=0, n, (n!/k!)^3); \\ Seiichi Manyama, May 02 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Sep 30 2012
STATUS
approved