cp's OEIS Frontend

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.

A368102 Total number of partitions of [n-s] whose block maxima sum to s, summed over all s.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 1, 1, 3, 2, 3, 6, 5, 9, 14, 13, 20, 40, 31, 56, 86, 105, 127, 227, 244, 394, 520, 665, 911, 1536, 1565, 2449, 3507, 4719, 5931, 9061, 11151, 16911, 21774, 29798, 39804, 60411, 71865, 104399, 144999, 197907, 253430, 370044, 478764, 694807
Offset: 0

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Author

Alois P. Heinz, Dec 11 2023

Keywords

Examples

			a(11) = 6: 123|4, 124|3, 13|24, 14|23, 1|2|34, 1|2345.
		

Crossrefs

Antidiagonal sums of A367955.
Cf. A365821.

Programs

  • Maple
    b:= proc(n, m) option remember; `if`(n=0, 1,
          b(n-1, m)*m + expand(x^n*b(n-1, m+1)))
        end:
    a:= n-> add(coeff(b(n-k, 0), x, k), k=ceil(n/2)..n):
    seq(a(n), n=0..80);
    # second Maple program:
    b:= proc(n, i, t) option remember; `if`(i*(i+1)/2 add(b(k, n-k, 0), k=ceil(n/2)..n):
    seq(a(n), n=0..80);
  • Mathematica
    b[n_, i_, t_] := b[n, i, t] = If[i*(i + 1)/2 < n, 0, If[n == 0, t^i, If[t == 0, 0, t*b[n, i - 1, t]] + (t + 1)^Max[0, 2*i - n - 1]*b[n - i, Min[n - i, i - 1], t + 1]]];
    a[n_] := If[n == 0, 1, Sum[b[k, n - k, 0], {k, Ceiling[n/2], n}]];
    Table[a[n], {n, 0, 80}] (* Jean-François Alcover, Oct 03 2024, after Alois P. Heinz *)