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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.

A134979 Triangle read by rows: T(n,k) = number of partitions of n where the maximum number of objects in partitions of any given size is k.

Original entry on oeis.org

1, 0, 2, 0, 1, 2, 0, 1, 1, 3, 0, 0, 3, 2, 2, 0, 0, 2, 4, 1, 4, 0, 0, 1, 6, 3, 3, 2, 0, 0, 1, 6, 4, 6, 1, 4, 0, 0, 0, 6, 7, 8, 3, 3, 3, 0, 0, 0, 5, 7, 14, 4, 6, 2, 4, 0, 0, 0, 5, 7, 18, 7, 9, 5, 3, 2, 0, 0, 0, 3, 10, 22, 9, 14, 6, 6, 1, 6, 0, 0, 0, 2, 9, 26, 15, 19, 11, 9, 3, 5, 2
Offset: 1

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Comments

Every column is eventually 0; the last row with a nonzero value in column k is A024916(k). T(A024916(k)-i, k) <= P(i), where P is the partition function (A000041); equality holds for 0 <= i <= k. The partition represented by the last number in column k is row k of A010766.

Examples

			For the partition [3,2^2], there are 3 objects in the part of size 3 and 4 objects in the parts of size 2, so this partition is counted towards T(7,4).
Triangle T(n,k) begins:
  1;
  0, 2;
  0, 1, 2;
  0, 1, 1, 3;
  0, 0, 3, 2,  2;
  0, 0, 2, 4,  1,  4;
  0, 0, 1, 6,  3,  3, 2;
  0, 0, 1, 6,  4,  6, 1,  4;
  0, 0, 0, 6,  7,  8, 3,  3, 3;
  0, 0, 0, 5,  7, 14, 4,  6, 2, 4;
  0, 0, 0, 5,  7, 18, 7,  9, 5, 3, 2;
  0, 0, 0, 3, 10, 22, 9, 14, 6, 6, 1, 6;
  ...
		

Crossrefs

Cf. A008284, A091602, A000041 (row sums), A000005 (main diagonal), A032741 (2nd diagonal), A010766.
Column sums give A332233.

Programs

  • Maple
    b:= proc(n, i, m) option remember; `if`(n=0 or i=1, x^
          max(m, n), add(b(n-i*j, i-1, max(m, i*j)), j=0..n/i))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=1..n))(b(n$2, 0)):
    seq(T(n), n=1..20);  # Alois P. Heinz, Feb 07 2020
  • Mathematica
    b[n_, i_, m_] := b[n, i, m] = If[n == 0 || i == 1, x^Max[m, n], Sum[b[n - i j, i - 1, Max[m, i j]], {j, 0, n/i}]];
    T[n_] := Table[Coefficient[b[n, n, 0], x, i], {i, 1, n}];
    Array[T, 20] // Flatten (* Jean-François Alcover, Nov 10 2020, after Alois P. Heinz *)