OFFSET
0,4
LINKS
Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 0..100
FORMULA
a(n) = A242351(n,n+3-ceiling(2*sqrt(n+2))).
MAPLE
b:= proc(n, i, t) option remember; `if`(n<1, 1, expand(add(
`if`(j>i, x, 1) *b(n-1, j, t+`if`(j=i, 1, 0)), j=0..t+1)))
end:
a:= n-> (p-> coeff(p, x, degree(p)))(b(n-1, 0$2)):
seq(a(n), n=0..50);
MATHEMATICA
b[n_, i_, t_] := b[n, i, t] = If[n < 1, 1, Expand[Sum[
If[j > i, x, 1]*b[n - 1, j, t + If[j == i, 1, 0]], {j, 0, t + 1}]]];
a[n_] := With[{p = b[n - 1, 0, 0]}, Coefficient[p, x, Exponent[p, x]]];
Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Aug 27 2021, after Maple code *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jun 01 2014
STATUS
approved