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A296188
Number of normal semistandard Young tableaux whose shape is the integer partition with Heinz number n.
49
1, 1, 2, 1, 4, 4, 8, 1, 6, 12, 16, 6, 32, 32, 28, 1, 64, 16, 128, 24, 96, 80, 256, 8, 44, 192, 22, 80, 512, 96, 1024, 1, 288, 448, 224, 30, 2048, 1024, 800, 40, 4096, 400, 8192, 240, 168, 2304, 16384, 10, 360, 204, 2112, 672, 32768, 68, 832, 160, 5376, 5120
OFFSET
1,3
COMMENTS
A tableau is normal if its entries span an initial interval of positive integers. The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
REFERENCES
Richard P. Stanley, Enumerative Combinatorics Volume 2, Cambridge University Press, 1999, Chapter 7.10.
LINKS
FindStat - Combinatorial Statistic Finder, Semistandard Young tableaux
FORMULA
Let b(n) = Sum_{d|n, d>1} b(n * d' / d) where if d = Product_i prime(s_i)^m(i) then d' = Product_i prime(s_i - 1)^m(i) and prime(0) = 1. Then a(n) = b(conj(n)) where conj = A122111.
EXAMPLE
The a(9) = 6 tableaux:
1 3 1 2 1 2 1 2 1 1 1 1
2 4 3 4 3 3 2 3 2 3 2 2
MATHEMATICA
conj[y_List]:=If[Length[y]===0, y, Table[Length[Select[y, #>=k&]], {k, 1, Max[y]}]];
conj[n_Integer]:=Times@@Prime/@conj[If[n===1, {}, Join@@Cases[FactorInteger[n]//Reverse, {p_, k_}:>Table[PrimePi[p], {k}]]]];
ssyt[n_]:=If[n===1, 1, Sum[ssyt[n/q*Times@@Cases[FactorInteger[q], {p_, k_}:>If[p===2, 1, NextPrime[p, -1]^k]]], {q, Rest[Divisors[n]]}]];
Table[ssyt[conj[n]], {n, 50}]
KEYWORD
nonn
AUTHOR
Gus Wiseman, Feb 14 2018
STATUS
approved