OFFSET
0,2
COMMENTS
Partial sums of 2*A055533.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..446
Mathematical Reflections, Problem J256, Issue 1, 2013, p 4.
Mathematical Reflections, Solution to Problem J256, Issue 2, 2013, p 4.
FORMULA
a(n) = (n - 1)*(n + 2)! + 2 (see 2nd Mathematical Reflections link). Cf. A052520.
E.g.f.: 2*exp(x) - 2*(1 - 4*x)/(1 - x)^4. - Ilya Gutkovskiy, Jan 05 2017
MAPLE
MATHEMATICA
Table[Sum[k^2 (k+1)!, {k, n}], {n, 0, 20}] (* Harvey P. Dale, Jun 05 2017 *)
PROG
(PARI) a(n) = sum(k=1, n, k^2*(k+1)!)
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Jan 05 2017
STATUS
approved