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.

A264078 The maximal number of standard Young tableaux without a succession v, v+1 in a row that a single partition of n can have.

Original entry on oeis.org

1, 1, 1, 1, 2, 3, 6, 14, 30, 76, 170, 553, 1583, 5106, 14090, 41002, 164769, 603513, 2418348, 8335804, 28704417, 109618261, 466318442, 2114095511, 10276979159, 43213859606, 175668903294, 793946150358, 3490939879402, 15500974371599, 82490059523125
Offset: 0

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Author

Alois P. Heinz, Nov 02 2015

Keywords

Comments

A standard Young tableau (SYT) without a succession v, v+1 in a row is called a nonconsecutive tableau.

Examples

			a(6) = 6: partition [2,2,1,1] has 6 standard Young tableaux without a succession v, v+1 in a row, which is maximal for a partition of n=6:
15   14   14   13   13   13
26   26   25   26   25   24
3    3    3    4    4    5
4    5    6    5    6    6
		

Crossrefs

Programs

  • Maple
    h:= proc(l, j) option remember; `if`(l=[], 1,
          `if`(l[1]=0, h(subsop(1=[][], l), j-1), add(
          `if`(i<>j and l[i]>0 and (i=1 or l[i]>l[i-1]),
           h(subsop(i=l[i]-1, l), i), 0), i=1..nops(l))))
        end:
    g:= proc(n, i, l) `if`(n=0 or i=1, h([1$n, l[]], 0),
          `if`(i<1, 0, max(g(n, i-1, l),
          `if`(i>n, 0, g(n-i, i, [i, l[]])))))
        end:
    a:= n-> g(n$2, []):
    seq(a(n), n=0..30);  # Alois P. Heinz, Nov 02 2015
  • Mathematica
    h[l_, j_] := h[l, j] = If[l == {}, 1, If[l[[1]] == 0, h[ReplacePart[l, 1 -> Sequence[]], j - 1], Sum[If[i != j && l[[i]] > 0 && (i == 1 || l[[i]] > l[[i - 1]]), h[ReplacePart[l, i -> l[[i]] - 1], i], 0], {i, 1, Length[l]} ]]]; g[n_, i_, l_] := g[n, i, l] = If[n == 0 || i == 1, h[Join[Array[1 &, n], l], 0], If[i < 1, 0, Max[g[n, i - 1, l], If[i > n, 0, g[n - i, i, Join[{i}, l]]]]]]; a[n_] := g[n, n, {}];  Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Jan 22 2016, after Alois P. Heinz *)

Formula

a(n) = max { k : A264051(n,k) > 0 }.