A007235 Structure constants for certain representations of S_n. (Formerly M4500)

8, 27, 384, 12100, 736128, 70990416, 9939419136, 1896254551296, 472882821120000, 149328979405056000, 58255835226557644800, 27519543889780053196800, 15483244831426302168268800, 10231838708930053383168000000

Offset

1,1

References

A. Goupil, Decomposition of certain products of conjugacy classes of S_n, J. Combin. Theory, A 66 (1994), 102-117.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=1..14.

Formula

a(n) = b(n, 2*n+2) where b(k, m) = (2 * m! / (k^2 * (m-k)^2)) * ((m / (m+1)) * (1 + (-1)^(k+1) / binomial(m, k)) + ((k+1) / binomial(m, k)) * Sum_{j=0..k-1} (j+1) / (binomial(k - 1, j) * binomial(k, j))) [from Goupil]. - Sean A. Irvine, Nov 23 2017

Crossrefs

Sequence in context: A028935 A030089 A348585 * A029789 A155930 A100519

Adjacent sequences: A007232 A007233 A007234 * A007236 A007237 A007238

Keyword

nonn

Author

Simon Plouffe

Extensions

More terms from Sean A. Irvine, Nov 23 2017

Status

approved