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 A299968 Number of normal generalized Young tableaux of size n with all rows and columns strictly increasing. 15

%I

%S 1,1,2,5,15,51,189,753,3248,14738,70658,354178,1857703,10121033

%N Number of normal generalized Young tableaux of size n with all rows and columns strictly increasing.

%C A generalized Young tableau of shape y is an array obtained by replacing the dots in the Ferrers diagram of y with positive integers. A tableau is normal if its entries span an initial interval of positive integers.

%H D. E. Knuth, <a href="https://projecteuclid.org/euclid.pjm/1102971948">Permutations, matrices, and generalized Young tableaux</a>, Pacific Journal of Mathematics, Vol. 34, No. 3 (1970), 709-727.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Young_tableau">Young tableau</a>

%e The a(4) = 15 tableaux:

%e 1 2 3 4

%e .

%e 1 2 3 1 2 4 1 3 4 1 2 3 1 2 3

%e 4 3 2 2 3

%e .

%e 1 2 1 3 1 2

%e 3 4 2 4 2 3

%e .

%e 1 2 1 3 1 2 1 4 1 3

%e 3 2 2 2 2

%e 4 4 3 3 3

%e .

%e 1

%e 2

%e 3

%e 4

%t unddis[y_]:=DeleteCases[y-#,0]&/@Tuples[Table[If[y[[i]]>Append[y,0][[i+1]],{0,1},{0}],{i,Length[y]}]];

%t dos[y_]:=With[{sam=Rest[unddis[y]]},If[Length[sam]===0,If[Total[y]===0,{{}},{}],Join@@Table[Prepend[#,y]&/@dos[sam[[k]]],{k,1,Length[sam]}]]];

%t Table[Sum[Length[dos[y]],{y,IntegerPartitions[n]}],{n,1,8}]

%Y Cf. A000085, A000898, A001221, A005117, A006958, A015128, A138178, A238690, A285175, A296561, A297388, A299926, A300120, A300122.

%K nonn,more

%O 0,3

%A _Gus Wiseman_, Feb 26 2018

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Last modified January 22 13:41 EST 2020. Contains 331149 sequences. (Running on oeis4.)