OFFSET
0,3
COMMENTS
For n > 0, equals one-half of the row sums of triangle A127126.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..80
MATHEMATICA
T[n_, k_]:= T[n, k]= If[k==n, 1, Coefficient[(1 +x*Sum[x^(r-k-1)*Sum[T[r, c], {c, k+1, r}], {r, k+1, n}] + x^(n+1))^(k+1), x, n-k]]; Table[T[n, 0], {n, 0, 20}] (* G. C. Greubel, Jan 28 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 05 2007
STATUS
approved