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A214776 Number A(n,k) of standard Young tableaux of shape [n*k,n]; square array A(n,k), n>=0, k>=0, read by antidiagonals. 19
1, 1, 0, 1, 1, 0, 1, 2, 2, 0, 1, 3, 9, 5, 0, 1, 4, 20, 48, 14, 0, 1, 5, 35, 154, 275, 42, 0, 1, 6, 54, 350, 1260, 1638, 132, 0, 1, 7, 77, 663, 3705, 10659, 9996, 429, 0, 1, 8, 104, 1120, 8602, 40480, 92092, 62016, 1430, 0, 1, 9, 135, 1748, 17199, 115101, 451269, 807300, 389367, 4862, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,8
COMMENTS
A(n,k) is also the number of binary words with n*k 1's and n 0's such that for every prefix the number of 1's is >= the number of 0's. The A(2,2) = 9 words are: 101011, 101101, 101110, 110011, 110101, 110110, 111001, 111010, 111100.
LINKS
Alois P. Heinz, Antidiagonals n = 0..140
Paul Barry, On the Central Antecedents of Integer (and Other) Sequences, J. Int. Seq., Vol. 23 (2020), Article 20.8.3.
Wikipedia, Young tableau
FORMULA
A(n,k) = max(0, C((k+1)*n,n)*((k-1)*n+1)/(k*n+1)).
EXAMPLE
Square array A(n,k) begins:
1, 1, 1, 1, 1, 1, 1, ...
0, 1, 2, 3, 4, 5, 6, ...
0, 2, 9, 20, 35, 54, 77, ...
0, 5, 48, 154, 350, 663, 1120, ...
0, 14, 275, 1260, 3705, 8602, 17199, ...
0, 42, 1638, 10659, 40480, 115101, 272272, ...
MAPLE
A:= (n, k)-> max(0, binomial((k+1)*n, n)*((k-1)*n+1)/(k*n+1)):
seq(seq(A(n, d-n), n=0..d), d=0..12);
MATHEMATICA
a[n_, k_] := Max[0, Binomial[(k+1)*n, n]*((k-1)*n+1)/(k*n+1)]; Table[Table[a[n, d-n], {n, 0, d}], {d, 0, 12}] // Flatten (* Jean-François Alcover, Oct 01 2013, after Maple *)
CROSSREFS
Main diagonal gives: A215557.
Sequence in context: A237018 A290605 A292913 * A369415 A317575 A295653
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Jul 28 2012
STATUS
approved

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)