OFFSET
0,3
LINKS
Geoffrey Critzer and Alois P. Heinz, Table of n, a(n) for n = 0..386
FORMULA
a(n) = [x^n] 1/(1-Sum_{i=1..n} v(i)/(1+v(i))) with v(i) = (x-x^(i+1))/(1-x).
a(n) ~ n^n. - Vaclav Kotesovec, Aug 27 2014
MAPLE
a:= proc(n) option remember; local v;
v:= i-> (x-x^(i+1))/(1-x);
coeff(series(1/(1-add(v(i)/(1+v(i)), i=1..n)), x, n+1), x, n)
end:
seq(a(n), n=0..25);
MATHEMATICA
b[n_, k_, c_, t_] := b[n, k, c, t] = If[n == 0, 1, Sum[If[c == t && j == c, 0, b[n - 1, k, j, 1 + If[j == c, t, 0]]], {j, 1, k}]];
a[n_] := b[n, n, 0, 0];
a /@ Range[0, 25] (* Jean-François Alcover, Dec 28 2020, from Maple code of A242464 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Critzer and Alois P. Heinz, May 19 2014
STATUS
approved