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.

A082733 Sum of all entries in character table of the symmetric group S_n.

Original entry on oeis.org

1, 2, 5, 13, 31, 89, 259, 842, 2810, 10020, 37266, 145373, 586071, 2453927, 10590180, 47159351, 215706629, 1013916313, 4882544468, 24087770591, 121481296510, 626169893024, 3293432146879, 17670096206819, 96589760733604, 537731396393480, 3045955783377644
Offset: 1

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Author

Vladeta Jovovic, May 20 2003

Keywords

Examples

			a(3) = 5 because the character table of S_3 is / 1 1 1 / 2 0 -1 / 1 -1 1 /.
		

Crossrefs

Programs

  • GAP
    A082733 := n -> Sum(Sum(Irr(CharacterTable("Symmetric", n)))); # Eric M. Schmidt, Jul 03 2012
  • Mathematica
    a[n_] := FiniteGroupData[{"SymmetricGroup", n}, "CharacterTable"] // Flatten // Total;
    Table[an = a[n]; Print[n, " ", an]; an, {n, 1, 10}] (* Jean-François Alcover, Nov 03 2018 *)

Formula

Let D(x) = Sum_{n>=0} (2n-1)!!*x^n = 1/(1 - x/(1 - 2x/(1 - 3x/...))) and R_r(x) = Sum_{n>=0} o_r(n)*x^n = 1/(1 - x - r*x^2/(1 - x - 2*r*x^2/(1 - x - 3*r*x^2/...))), where o_r(n) = Sum_{k=0..n/2} binomial(n, 2k)*(2k-1)!!*r^k. Then the generating function of this sequence is Sum_{n>=0} a(n)*x^n = Product_{i >= 1} (D(2ix^{4i}) * R_{2i-1}(x^{2i-1}). - Arvind Ayyer, Jun 11 2024

Extensions

More terms from Eric M. Schmidt, Jul 03 2012