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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.

A228125 Triangle read by rows: T(n,k) = number of semistandard Young tableaux with sum of entries equal to n and shape of tableau a partition of k.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 2, 1, 1, 4, 4, 2, 1, 1, 5, 7, 5, 2, 1, 1, 6, 10, 9, 5, 2, 1, 1, 7, 14, 16, 10, 5, 2, 1, 1, 8, 19, 24, 19, 11, 5, 2, 1, 1, 9, 24, 37, 32, 21, 11, 5, 2, 1, 1, 10, 30, 51, 52, 38, 22, 11, 5, 2, 1, 1, 11, 37, 71, 79, 66, 41, 23, 11, 5, 2, 1, 1, 12, 44, 93, 117, 106, 74, 43, 23, 11, 5, 2, 1, 1, 13, 52, 122, 166, 166, 125, 80, 44, 23, 11, 5, 2, 1, 1, 14, 61, 153, 231, 251, 204, 139, 83, 45, 23, 11, 5, 2, 1, 1, 15, 70, 193, 311, 367, 322, 236, 147, 85, 45, 23, 11, 5, 2, 1
Offset: 1

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Author

Wouter Meeussen, Aug 11 2013

Keywords

Comments

Row sums equal A003293.
Reverse of rows seem to converge to A005986: 1, 2, 5, 11, 23, 45, 87, 160, ...

Examples

			T(6,3) = 7 since the 7 SSYT with sum of entries = 6 and shape any partition of 3 are
114 , 123 , 222 , 11 ,  12  , 13 ,   1
                  4     3     2      2
                                     3
Triangle starts:
1;
1,  1;
1,  2,  1;
1,  3,  2,  1;
1,  4,  4,  2,  1;
1,  5,  7,  5,  2,  1;
1,  6, 10,  9,  5,  2,  1;
1,  7, 14, 16, 10,  5,  2,  1;
1,  8, 19, 24, 19, 11,  5,  2, 1;
1,  9, 24, 37, 32, 21, 11,  5, 2, 1;
1, 10, 30, 51, 52, 38, 22, 11, 5, 2, 1;
		

Crossrefs

Programs

  • Mathematica
    hooklength[(par_)?PartitionQ]:=Table[Count[par,q_ /; q>=j] +1-i +par[[i]] -j, {i,Length[par]}, {j,par[[i]]} ];
    Table[Tr[(SeriesCoefficient[q^(#1 . Range[Length[#1]])/Times @@ (1-q^#1&) /@ Flatten[hooklength[#1]],{q,0,w}]&) /@ Partitions[n]],{w,24},{n,w}]