OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..375
Vaclav Kotesovec, Plot of |a(n)/a(n-1)|/n for n = 1..1000
FORMULA
a(n) = hypergeom([-n, -n, -n], [1, 1], n). - Peter Luschny, Dec 22 2020
MAPLE
a := n -> hypergeom([-n, -n, -n], [1, 1], n):
seq(simplify(a(n)), n=0..18); # Peter Luschny, Dec 22 2020
MATHEMATICA
Array[Function[n, 1 + Sum[(-n)^k Binomial[n, k]^3, {k, n}]], 19, 0] (* Jan Mangaldan, Jul 14 2020 *)
PROG
(PARI) {a(n) = sum(k=0, n, (-n)^k*binomial(n, k)^3)}
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Jul 10 2020
STATUS
approved