OFFSET
0,3
FORMULA
E.g.f.: (Li_2(x+x^2-x^3) - Li_2(x))/(1-x), where Li_2(x) is the dilogarithm.
MATHEMATICA
a[n_] := n! * Sum[1/(m^2*(Binomial[n - m, m])), {m, 1, Floor[n/2]}]; Array[a, 21, 2] (* Amiram Eldar, Nov 25 2022 *)
PROG
(Maxima)
a(n):=sum(1/(m^2*(binomial(n-m, m))), m, 1, floor((n)/2));
(PARI) a(n) = n!*sum(m=1, n\2, 1/(m^2*binomial(n-m, m))); \\ Michel Marcus, Nov 25 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Kruchinin, Nov 25 2022
STATUS
approved