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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A259841 Number T(n,k) of elements k in all n X n Tesler matrices of nonnegative integers; triangle T(n,k), n>=1, 1<=k<=n, read by rows.

Original entry on oeis.org

1, 3, 1, 15, 5, 2, 117, 37, 17, 7, 1367, 418, 189, 100, 40, 23329, 7027, 3058, 1688, 939, 357, 570933, 171428, 72194, 39274, 24050, 13429, 4820, 19740068, 5948380, 2449366, 1293768, 807576, 517548, 283510, 96030
Offset: 1

Views

Author

Alois P. Heinz, Jul 06 2015

Keywords

Comments

For the definition of Tesler matrices see A008608.
Sum_{k=1..n} k * T(n,k) = A259787(n).

Examples

			There are two 2 X 2 Tesler matrices: [1,0; 0,1], [0,1; 0,2], containing three 1's and one 2, thus row 2 gives [3, 1].
Triangle T(n,k) begins:
       1;
       3,      1;
      15,      5,     2;
     117,     37,    17,     7;
    1367,    418,   189,   100,    40;
   23329,   7027,  3058,  1688,   939,   357;
  570933, 171428, 72194, 39274, 24050, 13429, 4820;
  ...
		

Crossrefs

Main diagonal gives A008608(n-1) for n>1.
Column k=1 gives A259843.
Row sums give A259842.
Cf. A259787.

Programs

  • Maple
    g:= u-> `if`(u=0, 0, x^u):
    b:= proc(n, i, l) option remember; (m->`if`(m=0, [1, g(n)], `if`(i=0,
         (p->p+[0, p[1]*g(n)])(b(l[1]+1, m-1, subsop(1=NULL, l))), add(
         (p->p+[0, p[1]*g(j)])(b(n-j, i-1, subsop(i=l[i]+j, l)))
          , j=0..n))))(nops(l))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=1..n))(b(1,n-1,[0$(n-1)])[2]):
    seq(T(n), n=1..10);
  • Mathematica
    g[u_] := If[u == 0, 0, x^u];
    b[n_, i_, l_] := b[n, i, l] = Function[m, If[m == 0, {1, g[n]}, If[i == 0, # + {0, #[[1]] g[n]} & [b[l[[1]]+1, m-1, ReplacePart[l, 1 -> Nothing]]], Sum[# + {0, #[[1]] g[j]} & [b[n-j, i-1, ReplacePart[l, i -> l[[i]] + j]]], {j, 0, n}]]]][Length[l]];
    T[n_] := Table[Coefficient[#, x, i], {i, 1, n}] & [b[1, n-1, Table[0, {n-1}]][[2]]];
    Array[T, 10] // Flatten (* Jean-François Alcover, Oct 28 2020, after Maple *)