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.

Showing 1-10 of 12 results. Next

A237770 Number of standard Young tableaux with n cells without a succession v, v+1 in a row.

Original entry on oeis.org

1, 1, 1, 2, 4, 9, 22, 59, 170, 516, 1658, 5583, 19683, 72162, 274796, 1082439, 4406706, 18484332, 79818616, 353995743, 1611041726, 7510754022, 35842380314, 174850257639, 871343536591, 4430997592209, 22978251206350, 121410382810005, 653225968918521
Offset: 0

Views

Author

Joerg Arndt and Alois P. Heinz, Feb 13 2014

Keywords

Comments

A standard Young tableau (SYT) without a succession v, v+1 in a row is called a nonconsecutive tableau.
Also the number of ballot sequences without two consecutive elements equal. A ballot sequence B is a string such that, for all prefixes P of B, h(i)>=h(j) for iA000085).
First column (k=0) of A238125.

Examples

			The a(5) = 9 such tableaux of 5 are:
[1]   [2]  [3]   [4]  [5]  [6]  [7]  [8]  [9]
135   13   135   13   13   14   14   15   1
24    24   2     25   2    25   2    2    2
      5    4     4    4    3    3    3    3
                      5         5    4    4
                                          5
The corresponding ballot sequences are:
1:  [ 0 1 0 1 0 ]
2:  [ 0 1 0 1 2 ]
3:  [ 0 1 0 2 0 ]
4:  [ 0 1 0 2 1 ]
5:  [ 0 1 0 2 3 ]
6:  [ 0 1 2 0 1 ]
7:  [ 0 1 2 0 3 ]
8:  [ 0 1 2 3 0 ]
9:  [ 0 1 2 3 4 ]
		

Crossrefs

Cf. A000085 (all Young tableaux), A000957, A001181, A214021, A214087, A214159, A214875.
Cf. A238126 (tableaux with one succession), A238127 (two successions).

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, g(n, i-1, l)+
          `if`(i>n, 0, g(n-i, i, [i, l[]]))))
        end:
    a:= n-> g(n, n, []):
    seq(a(n), n=0..30);
    # second Maple program (counting ballot sequences):
    b:= proc(n, v, l) option remember;
          `if`(n<1, 1, add(`if`(i<>v and (i=1 or l[i-1]>l[i]),
           b(n-1, i, subsop(i=l[i]+1, l)), 0), i=1..nops(l))+
           b(n-1, nops(l)+1, [l[], 1]))
        end:
    a:= proc(n) option remember; forget(b); b(n-1, 1, [1]) end:
    seq(a(n), n=0..30);
  • Mathematica
    b[n_, v_, l_List] := b[n, v, l] = If[n<1, 1, Sum[If[i != v && (i == 1 || l[[i-1]] > l[[i]]), b[n-1, i, ReplacePart[l, i -> l[[i]]+1]], 0], {i, 1, Length[l]}] + b[n-1, Length[l]+1, Append[l, 1]]]; a[n_] := a[n] = b[n-1, 1, {1}]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Feb 06 2015, translated from 2nd Maple program *)

Formula

a(n) = Sum_{k=1..A264078(n)} k * A264051(n,k). - Alois P. Heinz, Nov 02 2015

A238126 Number of standard Young tableaux with n cells and exactly one succession.

Original entry on oeis.org

0, 0, 1, 1, 3, 8, 24, 70, 224, 744, 2588, 9317, 34924, 135297, 542123, 2236834, 9508297, 41511215, 186109781, 854874944, 4021672983, 19344343843, 95093249014, 477137036748, 2442413708120, 12742038926613, 67714763161526, 366266085720565, 2015454903261855
Offset: 0

Views

Author

Joerg Arndt and Alois P. Heinz, Feb 21 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having one flat step.
Second column (k=1) of A238125.

Crossrefs

Cf. A237770 (no successions), A238127 (two successions).

A238127 Number of standard Young tableaux with n cells and exactly two successions.

Original entry on oeis.org

0, 0, 0, 1, 2, 6, 17, 57, 191, 663, 2415, 9108, 35695, 143989, 599802, 2566917, 11298164, 50967216, 235745644, 1115324000, 5397332497, 26669487517, 134528555379, 691856601631, 3626390958551, 19353306241764, 105122093620388, 580689432523534, 3260906342453966
Offset: 0

Views

Author

Joerg Arndt and Alois P. Heinz, Feb 21 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having two flat steps.
Third column (k=2) of A238125.

Crossrefs

Cf. A237770 (no successions), A238126 (one succession).

A241774 Number of standard Young tableaux with n cells and exactly three successions.

Original entry on oeis.org

1, 2, 9, 29, 108, 399, 1573, 6249, 25642, 107751, 466898, 2071183, 9429453, 43889227, 209111720, 1017353435, 5056450994, 25627110560, 132451351403, 697165582228, 3736595119730, 20372395392794, 112961465325799, 636497947945382, 3643481367551384
Offset: 4

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having three flat steps.

Crossrefs

Column k=3 of A238125.

A241775 Number of standard Young tableaux with n cells and exactly four successions.

Original entry on oeis.org

1, 3, 13, 49, 201, 802, 3343, 14368, 62909, 282989, 1299074, 6111610, 29330177, 143869556, 719339872, 3669604633, 19062972671, 100880716332, 543086732800, 2974442015323, 16556687511535, 93655725178808, 537951557765438, 3137040309057826, 18560431188723607
Offset: 5

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having four flat steps.

Crossrefs

Column k=4 of A238125.

A241776 Number of standard Young tableaux with n cells and exactly five successions.

Original entry on oeis.org

1, 3, 17, 69, 322, 1408, 6440, 29555, 139005, 662522, 3228150, 15994167, 80849918, 415684406, 2177223330, 11594426886, 62826444538, 345909306526, 1935762918301, 10999013559517, 63460591709283, 371497097807233, 2206388300667674, 13286470507994738
Offset: 6

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having five flat steps.

Crossrefs

Column k=5 of A238125.

A241777 Number of standard Young tableaux with n cells and exactly six successions.

Original entry on oeis.org

1, 4, 23, 104, 510, 2411, 11661, 57226, 283833, 1434373, 7346663, 38317226, 202773341, 1091360787, 5961577175, 33093602158, 186413366123, 1066200757106, 6185213644077, 36404110664402, 217206981954701, 1313899575466329, 8052745347023754, 50003529679287381
Offset: 7

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having six flat steps.

Crossrefs

Column k=6 of A238125.

A241778 Number of standard Young tableaux with n cells and exactly seven successions.

Original entry on oeis.org

1, 4, 28, 137, 751, 3797, 19868, 103169, 544446, 2892654, 15609326, 85185225, 471914661, 2647616529, 15072126865, 86928421109, 508477806633, 3013152898489, 18098553323837, 110098999926894, 678500886312946, 4233264326440478, 26741870913391272
Offset: 8

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having seven flat steps.

Crossrefs

Column k=7 of A238125.

A241779 Number of standard Young tableaux with n cells and exactly eight successions.

Original entry on oeis.org

1, 5, 35, 189, 1088, 5896, 32419, 178832, 989799, 5540426, 31252470, 178571351, 1030696863, 6025834797, 35625675885, 213326126842, 1292327704580, 7927146783432, 49194730886734, 309011198106985, 1963433004838204, 12622320085676279, 82061043600221160
Offset: 9

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having eight flat steps.

Crossrefs

Column k=8 of A238125.

A241780 Number of standard Young tableaux with n cells and exactly nine successions.

Original entry on oeis.org

1, 5, 42, 238, 1499, 8635, 50873, 294903, 1724689, 10094399, 59679199, 355198229, 2136972743, 12972026795, 79626155414, 493684963581, 3095482758334, 19612796554079, 125656314294772, 813576800235695, 5325370849930701, 35223931484275717, 235474448496780769
Offset: 10

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

Comments

A succession is a pair of cells (v, v+1) lying in the same row.
Also number of ballot sequences having nine flat steps.

Crossrefs

Column k=9 of A238125.
Showing 1-10 of 12 results. Next