A214088
Number A(n,k) of n X k nonconsecutive chess tableaux; square array A(n,k), n>=0, k>=0, read by antidiagonals.
Original entry on oeis.org
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
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, ...
- 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
-
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$n], 0)):
seq(seq(A(n, d-n), n=0..d), d=0..14);
-
b[l_, t_] := b[l, t] = Module[{n, s}, {n, s} = {Length[l], Sum[i, {i, l}]};
If[s == 0, 1, Sum[If[t != i && Mod[s + i - l[[i]], 2] == 1 && l[[i]] > If[i == n, 0, l[[i+1]]], b[ReplacePart[l, {i -> l[[i]]-1}], i], 0], {i, 1, n}]] ]; a [n_, k_] := If[n < 1 || k < 1, 1, b[Array[k&, n], 0]]; Table[Table[a[n, d-n], {n, 0, d}], {d, 0, 14}] // Flatten (* Jean-François Alcover, Dec 11 2013, translated from Maple *)
A238020
Number of nonconsecutive chess tableaux with n cells.
Original entry on oeis.org
1, 1, 1, 1, 2, 2, 4, 5, 10, 15, 33, 52, 126, 213, 537, 991, 2563, 5118, 13670, 29171, 81069, 180813, 525755, 1216996, 3693934, 8843831, 27797975, 69106326, 223116931, 577433770, 1903516721, 5136516772, 17257698892, 48388514996, 166022450140, 481137194184
Offset: 0
a(6) = 4:
[1] [1 6] [1 4] [1 4]
[2] [2] [2 5] [2 5]
[3] [3] [3] [3 6]
[4] [4] [6]
[5] [5]
[6]
- Alois P. Heinz, Table of n, a(n) for n = 0..50
- T. Y. Chow, H. Eriksson and C. K. Fan, Chess tableaux, Elect. J. Combin., 11 (2) (2005), #A3.
- Jonas Sjöstrand, On the sign-imbalance of partition shapes, arXiv:math/0309231v3 [math.CO], 2005.
- Wikipedia, Young tableau
-
b:= proc(l, t) option remember; local n, s;
n, s:= nops(l), add(i, i=l); `if`(s=0, 1, add(`if`(t<>i and
irem(s+i-l[i], 2)=1 and l[i]>`if`(i=n, 0, l[i+1]), b(subsop(
i=`if`(i=n and l[n]=1, [][], l[i]-1), l), i), 0), i=1..n))
end:
g:= (n, i, l)-> `if`(n=0 or i=1, b([l[], 1$n], 0), `if`(i<1, 0,
add(g(n-i*j, i-1, [l[], i$j]), j=0..n/i))):
a:= n-> g(n, n, []):
seq(a(n), n=0..32);
-
b[l_, t_] := b[l, t] = Module[{ n = Length[l], s = Total[l]}, If[s == 0, 1, Sum[If[t != i && Mod[s + i - l[[i]], 2] == 1 && l[[i]] > If[i == n, 0, l[[i + 1]]], b[ReplacePart[l, i -> If[i == n && l[[n]] == 1, Nothing, l[[i]] - 1]], i], 0], {i, 1, n}]]];
g[n_, i_, l_] := If[n == 0 || i == 1, b[Join[l, Table[1, n]], 0], If[i < 1, 0, Sum[g[n - i*j, i - 1, Join[l, Table[i, j]]], {j, 0, n/i}]]];
a[n_] := g[n, n, {}];
Table[a[n], {n, 0, 32}] (* Jean-François Alcover, Nov 08 2017, after Alois P. Heinz *)
A238184
Sum of the squares of numbers of nonconsecutive chess tableaux over all partitions of n.
Original entry on oeis.org
1, 1, 1, 1, 2, 2, 4, 7, 16, 37, 107, 282, 1020, 2879, 12507, 39347, 179231, 687974, 3225246, 14955561, 75999551, 392585613, 2271201137, 12183159188, 81562521256, 446611878413, 3336304592155, 19202329389234, 152803821604669, 958953289839930, 7835058287650579
Offset: 0
a(7) = 1 + 2^2 + 1 + 1 = 7:
.
: [1111111] : [22111] : [3211] : [322] : <- shapes
:-----------+--------------+---------+---------:
: [1] : [1 6] [1 4] : [1 4 7] : [1 4 7] :
: [2] : [2 7] [2 5] : [2 5] : [2 5] :
: [3] : [3] [3] : [3] : [3 6] :
: [4] : [4] [6] : [6] : :
: [5] : [5] [7] : : :
: [6] : : : :
: [7] : : : :
- Alois P. Heinz, Table of n, a(n) for n = 0..50
- T. Y. Chow, H. Eriksson and C. K. Fan, Chess tableaux, Elect. J. Combin., 11 (2) (2005), #A3.
- Jonas Sjöstrand, On the sign-imbalance of partition shapes, arXiv:math/0309231v3 [math.CO], 2005.
- Wikipedia, Young tableau
-
b:= proc(l, t) option remember; local n, s;
n, s:= nops(l), add(i, i=l); `if`(s=0, 1, add(`if`(t<>i and
irem(s+i-l[i], 2)=1 and l[i]>`if`(i=n, 0, l[i+1]), b(subsop(
i=`if`(i=n and l[n]=1, [][], l[i]-1), l), i), 0), i=1..n))
end:
g:= (n, i, l)-> `if`(n=0 or i=1, b([l[], 1$n], 0)^2, `if`(i<1, 0,
add(g(n-i*j, i-1, [l[], i$j]), j=0..n/i))):
a:= n-> g(n, n, []):
seq(a(n), n=0..32);
-
b[l_, t_] := b[l, t] = Module[{n, s}, {n, s} = {Length[l], Total[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 -> If[i==n && l[[n]]==1, Nothing, l[[i]]-1]], i], 0], {i, 1, n}]]]; g[n_, i_, l_] := g[n, i, l] = If[n==0 || i==1, b[Join[l, Array[1&, n]], 0]^2, If[i<1, 0, Sum[g[n-i*j, i-1, Join[l, Array[i&, j]]], {j, 0, n/i}]]]; a[n_] := g[n, n, {}]; Table[a[n], {n, 0, 32}] (* Jean-François Alcover, Feb 17 2017, translated from Maple *)
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