cp's OEIS Frontend

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.

A318558 Number of degrees of irreducible representations of symmetric group S_n that appear more than once.

Original entry on oeis.org

0, 0, 1, 1, 2, 3, 4, 6, 10, 14, 20, 26, 35, 43, 49, 77, 103, 125, 174, 190, 274, 340, 430, 496, 686, 838, 1026, 1263, 1579, 1832, 2457, 2833, 3631, 4249, 5114, 6111, 7962, 9072, 11015, 12939, 16173, 18304, 23101, 26188, 31822, 37518, 45073, 51403, 63489, 71822
Offset: 0

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Author

Pierandrea Formusa, Aug 28 2018

Keywords

Examples

			Number 4 has the following partitions: a) [4], b) [3, 1], c) [2, 2], d) [2, 1, 1], e) [1, 1, 1, 1]. For partition a the cardinality of standard Young tableaux is 1, for b 3, for c 2, for d 3 and for e 1, so multiple cardinalities are 1 and 3: two multiple cardinalities, i.e., 4th sequence element is 2.
		

Crossrefs

Programs

  • Mathematica
    h[l_] := With[{n = Length[l]}, Total[l]!/Product[Product[1 + l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i + 1, n}], {j, 1, l[[i]]}], {i, 1, n}]];
    g[n_, i_, l_] := If[n == 0 || i == 1, h[Join[l, Array[1&, n]]], If[i < 1, 0, Flatten@ Table[g[n - i*j, i - 1, Join[l, Array[i&, j]]], {j, 0, n/i}]]];
    a[n_] := a[n] = If[n == 0 || n == 1, 0, Count[Tally[g[n, n, {}]], {, k /; k > 1}] ];
    Table[Print[n, " ", a[n]]; a[n], {n, 0, 49}] (* Jean-François Alcover, Sep 23 2024, after Alois P. Heinz in A060240 *)
  • SageMath
    r=""
    lista=[]
    lista_rip=[]
    rip=0
    for i in range(1,35):
            l=Partitions(i)
            for p in l:
                nsc=StandardTableaux(p).cardinality()
                if nsc in lista:
                    if nsc not in lista_rip:
                        lista_rip.append(nsc)
                        rip += 1
                else:
                    lista.append(nsc)
            r = r+","+str(rip)
            rip=0
            lista=[]
            lista_rip=[]
    print(r)

Formula

a(n) = A060437(n) - A060426(n). - Alois P. Heinz, Aug 29 2018

Extensions

a(42)-a(49) from Alois P. Heinz, Aug 29 2018