OFFSET
0,20
LINKS
Alois P. Heinz, Antidiagonals n = 0..140, flattened
M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to arXiv version]
M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to Lin. Alg. Applic. version together with omitted figures]
EXAMPLE
Square array A(n,k) begins:
0, 0, 0, 0, 0, 0, 0, 0, 0, ...
1, 1, 1, 1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, 1, 1, 1, ...
1, 2, 3, 4, 5, 6, 7, 8, 9, ...
1, 3, 6, 10, 15, 21, 28, 36, 45, ...
1, 6, 16, 32, 55, 86, 126, 176, 237, ...
1, 12, 43, 105, 210, 371, 602, 918, 1335, ...
1, 25, 120, 356, 826, 1647, 2961, 4936, 7767, ...
MAPLE
wtr:= proc(p) local b; b:= proc(n, i) option remember;
`if`(n=0, 1, `if`(i<1, 0, add(binomial(p(i), j)*
b(n-i*j, i-1), j=0..n/i))) end: j-> b(j$2)
end:
g:= proc(k) option remember; local b, t; b[0]:= j->
`if`(j<2, j, b[k](j-1)); for t to k do
b[t]:= wtr(b[t-1]) od: eval(b[0])
end:
A:= (n, k)-> g(k)(n):
seq(seq(A(n, d-n), n=0..d), d=0..14);
MATHEMATICA
wtr[p_] := Module[{b}, b[n_, i_] := b[n, i] = If[n == 0, 1, If[i < 1, 0, Sum[Binomial[p[i], j]*b[n - i*j, i - 1], {j, 0, n/i}]]]; b[#, #]&];
g[k_] := g[k] = Module[{b, t}, b[0][j_] := If[j < 2, j, b[k][j - 1]]; For[ t = 1, t <= k + 1, t++, b[t] = wtr[b[t - 1]]]; b[0]];
A[n_, k_] := g[k][n];
Table[A[n, d-n], {d, 0, 14}, {n, 0, d}] // Flatten (* Jean-François Alcover, Jul 10 2018, after Alois P. Heinz *)
CROSSREFS
KEYWORD
AUTHOR
Alois P. Heinz, Jun 24 2018
STATUS
approved