A214088 Number A(n,k) of n X k nonconsecutive chess tableaux; square array A(n,k), n>=0, k>=0, read by antidiagonals.
1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1, 1, 2, 1, 1, 1, 0, 0, 1, 0, 7, 0, 1, 1, 1, 0, 0, 1, 1, 35, 27, 5, 1, 1, 1, 0, 0, 1, 0, 212, 0, 128, 0, 1, 1, 1, 0, 0, 1, 1, 1421, 5075, 6212, 640, 14, 1, 1, 1, 0, 0, 1, 0, 10128, 0, 430275, 0, 3351, 0, 1, 1
Offset: 0
Examples
A(3,5) = 1: [1 4 7 10 13] [2 5 8 11 14] [3 6 9 12 15]. A(7,2) = 5: [1 8] [1 6] [1 4] [1 6] [1 4] [2 9] [2 7] [2 5] [2 7] [2 5] [3 10] [3 10] [3 10] [3 8] [3 8] [4 11] [4 11] [6 11] [4 9] [6 9] [5 12] [5 12] [7 12] [5 12] [7 12] [6 13] [8 13] [8 13] [10 13] [10 13] [7 14] [9 14] [9 14] [11 14] [11 14]. Square array A(n,k) begins: 1, 1, 1, 1, 1, 1, 1, 1, ... 1, 1, 0, 0, 0, 0, 0, 0, ... 1, 1, 0, 0, 0, 0, 0, 0, ... 1, 1, 1, 1, 1, 1, 1, 1, ... 1, 1, 0, 1, 0, 1, 0, 1, ... 1, 1, 2, 7, 35, 212, 1421, 10128, ... 1, 1, 0, 27, 0, 5075, 0, 2402696, ... 1, 1, 5, 128, 6212, 430275, 42563460, 5601745187, ...
Links
- Alois P. Heinz, Antidiagonals n = 0..21, flattened
- T. Y. Chow, H. Eriksson and C. K. Fan, Chess tableaux, Elect. J. Combin., 11 (2) (2005), #A3.
- Jonas Sjöstrand, On the sign-imbalance of partition shapes, arXiv:math/0309231v3 [math.CO], 2005.
- Wikipedia, Young tableau
Crossrefs
Programs
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Maple
b:= proc(l, t) option remember; local n, s; n, s:= nops(l), add(i, i=l); `if`(s=0, 1, add(`if`(t<>i and irem(s+i-l[i], 2)=1 and l[i]> `if`(i=n, 0, l[i+1]), b(subsop(i=l[i]-1, l), i), 0), i=1..n)) end: A:= (n, k)-> `if`(n<1 or k<1, 1, b([k$n], 0)): seq(seq(A(n, d-n), n=0..d), d=0..14);
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Mathematica
b[l_, t_] := b[l, t] = Module[{n, s}, {n, s} = {Length[l], Sum[i, {i, l}]}; If[s == 0, 1, Sum[If[t != i && Mod[s + i - l[[i]], 2] == 1 && l[[i]] > If[i == n, 0, l[[i+1]]], b[ReplacePart[l, {i -> l[[i]]-1}], i], 0], {i, 1, n}]] ]; a [n_, k_] := If[n < 1 || k < 1, 1, b[Array[k&, n], 0]]; Table[Table[a[n, d-n], {n, 0, d}], {d, 0, 14}] // Flatten (* Jean-François Alcover, Dec 11 2013, translated from Maple *)
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