OFFSET
0,4
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..6
MAPLE
b:= proc(u, o) option remember;
`if`(u+o=0, 1, add(b(o-1+j, u-j), j=1..u))
end:
a:= n-> (f-> f(f(n+1))-f(f(n)))(k-> b(k, 0)):
seq(a(n), n=0..5); # Alois P. Heinz, Aug 17 2021
MATHEMATICA
$RecursionLimit = Infinity;
t[n_, 0] := Boole[n == 0];
t[n_, k_] := t[n, k] = t[n, k-1] + t[n-1, n-k];
f[n_] := t[n, n];
a[n_] := f[f[n+1]] - f[f[n]];
Table[a[n], {n, 0, 5}] (* Jean-François Alcover, Apr 25 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 12 2005
EXTENSIONS
Definition corrected by N. J. A. Sloane, Feb 14 2018
STATUS
approved