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*       Copyright (C) 2019 The FindStatCrew <info@findstat.org>             *
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-----------------------------------------------------------------------------
Statistic identifier: St001123

-----------------------------------------------------------------------------
Collection: Integer partitions

-----------------------------------------------------------------------------
Description: The multiplicity of the dual of the standard representation in the Kronecker square corresponding to a partition.

The Kronecker coefficient is the multiplicity $g_{\mu,\nu}^\lambda$ of the Specht module $S^\lambda$ in $S^\mu\otimes S^\nu$:

$$ S^\mu\otimes S^\nu = \bigoplus_\lambda g_{\mu,\nu}^\lambda S^\lambda $$

This statistic records the Kronecker coefficient $g_{\lambda,\lambda}^{21^{n-2}}$, for $\lambda\vdash n$.

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References: [1]   [[wikipedia:Kronecker coefficient]]

-----------------------------------------------------------------------------
Code:
from sage.libs.symmetrica.symmetrica import charvalue_symmetrica as chv
def kronecker_coefficient(*partns):
    if partns == ():
        return 1
    else:
        return sum(mul(chv(la,mu) for la in partns)/mu.centralizer_size() for mu in Partitions(sum(partns[0])))

def statistic(la):
    return kronecker_coefficient(la,la,[2]+[1]*(la.size()-2))


-----------------------------------------------------------------------------
Statistic values:

[2]                       => 1
[1,1]                     => 1
[3]                       => 0
[2,1]                     => 1
[1,1,1]                   => 0
[4]                       => 0
[3,1]                     => 1
[2,2]                     => 0
[2,1,1]                   => 1
[1,1,1,1]                 => 0
[5]                       => 0
[4,1]                     => 0
[3,2]                     => 1
[3,1,1]                   => 1
[2,2,1]                   => 1
[2,1,1,1]                 => 0
[1,1,1,1,1]               => 0
[6]                       => 0
[5,1]                     => 0
[4,2]                     => 0
[4,1,1]                   => 1
[3,3]                     => 0
[3,2,1]                   => 2
[3,1,1,1]                 => 1
[2,2,2]                   => 0
[2,2,1,1]                 => 0
[2,1,1,1,1]               => 0
[1,1,1,1,1,1]             => 0
[7]                       => 0
[6,1]                     => 0
[5,2]                     => 0
[5,1,1]                   => 0
[4,3]                     => 0
[4,2,1]                   => 1
[4,1,1,1]                 => 1
[3,3,1]                   => 1
[3,2,2]                   => 1
[3,2,1,1]                 => 1
[3,1,1,1,1]               => 0
[2,2,2,1]                 => 0
[2,2,1,1,1]               => 0
[2,1,1,1,1,1]             => 0
[1,1,1,1,1,1,1]           => 0
[8]                       => 0
[7,1]                     => 0
[6,2]                     => 0
[6,1,1]                   => 0
[5,3]                     => 0
[5,2,1]                   => 0
[5,1,1,1]                 => 1
[4,4]                     => 0
[4,3,1]                   => 0
[4,2,2]                   => 0
[4,2,1,1]                 => 2
[4,1,1,1,1]               => 1
[3,3,2]                   => 1
[3,3,1,1]                 => 0
[3,2,2,1]                 => 0
[3,2,1,1,1]               => 0
[3,1,1,1,1,1]             => 0
[2,2,2,2]                 => 0
[2,2,2,1,1]               => 0
[2,2,1,1,1,1]             => 0
[2,1,1,1,1,1,1]           => 0
[1,1,1,1,1,1,1,1]         => 0
[9]                       => 0
[8,1]                     => 0
[7,2]                     => 0
[7,1,1]                   => 0
[6,3]                     => 0
[6,2,1]                   => 0
[6,1,1,1]                 => 0
[5,4]                     => 0
[5,3,1]                   => 0
[5,2,2]                   => 0
[5,2,1,1]                 => 1
[5,1,1,1,1]               => 1
[4,4,1]                   => 0
[4,3,2]                   => 1
[4,3,1,1]                 => 1
[4,2,2,1]                 => 1
[4,2,1,1,1]               => 1
[4,1,1,1,1,1]             => 0
[3,3,3]                   => 0
[3,3,2,1]                 => 1
[3,3,1,1,1]               => 0
[3,2,2,2]                 => 0
[3,2,2,1,1]               => 0
[3,2,1,1,1,1]             => 0
[3,1,1,1,1,1,1]           => 0
[2,2,2,2,1]               => 0
[2,2,2,1,1,1]             => 0
[2,2,1,1,1,1,1]           => 0
[2,1,1,1,1,1,1,1]         => 0
[1,1,1,1,1,1,1,1,1]       => 0
[10]                      => 0
[9,1]                     => 0
[8,2]                     => 0
[8,1,1]                   => 0
[7,3]                     => 0
[7,2,1]                   => 0
[7,1,1,1]                 => 0
[6,4]                     => 0
[6,3,1]                   => 0
[6,2,2]                   => 0
[6,2,1,1]                 => 0
[6,1,1,1,1]               => 1
[5,5]                     => 0
[5,4,1]                   => 0
[5,3,2]                   => 0
[5,3,1,1]                 => 0
[5,2,2,1]                 => 0
[5,2,1,1,1]               => 2
[5,1,1,1,1,1]             => 1
[4,4,2]                   => 0
[4,4,1,1]                 => 0
[4,3,3]                   => 1
[4,3,2,1]                 => 3
[4,3,1,1,1]               => 0
[4,2,2,2]                 => 0
[4,2,2,1,1]               => 0
[4,2,1,1,1,1]             => 0
[4,1,1,1,1,1,1]           => 0
[3,3,3,1]                 => 1
[3,3,2,2]                 => 0
[3,3,2,1,1]               => 0
[3,3,1,1,1,1]             => 0
[3,2,2,2,1]               => 0
[3,2,2,1,1,1]             => 0
[3,2,1,1,1,1,1]           => 0
[3,1,1,1,1,1,1,1]         => 0
[2,2,2,2,2]               => 0
[2,2,2,2,1,1]             => 0
[2,2,2,1,1,1,1]           => 0
[2,2,1,1,1,1,1,1]         => 0
[2,1,1,1,1,1,1,1,1]       => 0
[1,1,1,1,1,1,1,1,1,1]     => 0
[11]                      => 0
[10,1]                    => 0
[9,2]                     => 0
[9,1,1]                   => 0
[8,3]                     => 0
[8,2,1]                   => 0
[8,1,1,1]                 => 0
[7,4]                     => 0
[7,3,1]                   => 0
[7,2,2]                   => 0
[7,2,1,1]                 => 0
[7,1,1,1,1]               => 0
[6,5]                     => 0
[6,4,1]                   => 0
[6,3,2]                   => 0
[6,3,1,1]                 => 0
[6,2,2,1]                 => 0
[6,2,1,1,1]               => 1
[6,1,1,1,1,1]             => 1
[5,5,1]                   => 0
[5,4,2]                   => 0
[5,4,1,1]                 => 0
[5,3,3]                   => 0
[5,3,2,1]                 => 1
[5,3,1,1,1]               => 1
[5,2,2,2]                 => 0
[5,2,2,1,1]               => 1
[5,2,1,1,1,1]             => 1
[5,1,1,1,1,1,1]           => 0
[4,4,3]                   => 0
[4,4,2,1]                 => 1
[4,4,1,1,1]               => 0
[4,3,3,1]                 => 2
[4,3,2,2]                 => 1
[4,3,2,1,1]               => 1
[4,3,1,1,1,1]             => 0
[4,2,2,2,1]               => 0
[4,2,2,1,1,1]             => 0
[4,2,1,1,1,1,1]           => 0
[4,1,1,1,1,1,1,1]         => 0
[3,3,3,2]                 => 0
[3,3,3,1,1]               => 0
[3,3,2,2,1]               => 0
[3,3,2,1,1,1]             => 0
[3,3,1,1,1,1,1]           => 0
[3,2,2,2,2]               => 0
[3,2,2,2,1,1]             => 0
[3,2,2,1,1,1,1]           => 0
[3,2,1,1,1,1,1,1]         => 0
[3,1,1,1,1,1,1,1,1]       => 0
[2,2,2,2,2,1]             => 0
[2,2,2,2,1,1,1]           => 0
[2,2,2,1,1,1,1,1]         => 0
[2,2,1,1,1,1,1,1,1]       => 0
[2,1,1,1,1,1,1,1,1,1]     => 0
[1,1,1,1,1,1,1,1,1,1,1]   => 0
[12]                      => 0
[11,1]                    => 0
[10,2]                    => 0
[10,1,1]                  => 0
[9,3]                     => 0
[9,2,1]                   => 0
[9,1,1,1]                 => 0
[8,4]                     => 0
[8,3,1]                   => 0
[8,2,2]                   => 0
[8,2,1,1]                 => 0
[8,1,1,1,1]               => 0
[7,5]                     => 0
[7,4,1]                   => 0
[7,3,2]                   => 0
[7,3,1,1]                 => 0
[7,2,2,1]                 => 0
[7,2,1,1,1]               => 0
[7,1,1,1,1,1]             => 1
[6,6]                     => 0
[6,5,1]                   => 0
[6,4,2]                   => 0
[6,4,1,1]                 => 0
[6,3,3]                   => 0
[6,3,2,1]                 => 0
[6,3,1,1,1]               => 0
[6,2,2,2]                 => 0
[6,2,2,1,1]               => 0
[6,2,1,1,1,1]             => 2
[6,1,1,1,1,1,1]           => 1
[5,5,2]                   => 0
[5,5,1,1]                 => 0
[5,4,3]                   => 0
[5,4,2,1]                 => 0
[5,4,1,1,1]               => 0
[5,3,3,1]                 => 1
[5,3,2,2]                 => 0
[5,3,2,1,1]               => 3
[5,3,1,1,1,1]             => 0
[5,2,2,2,1]               => 0
[5,2,2,1,1,1]             => 0
[5,2,1,1,1,1,1]           => 0
[5,1,1,1,1,1,1,1]         => 0
[4,4,4]                   => 0
[4,4,3,1]                 => 1
[4,4,2,2]                 => 1
[4,4,2,1,1]               => 0
[4,4,1,1,1,1]             => 0
[4,3,3,2]                 => 1
[4,3,3,1,1]               => 1
[4,3,2,2,1]               => 0
[4,3,2,1,1,1]             => 0
[4,3,1,1,1,1,1]           => 0
[4,2,2,2,2]               => 0
[4,2,2,2,1,1]             => 0
[4,2,2,1,1,1,1]           => 0
[4,2,1,1,1,1,1,1]         => 0
[4,1,1,1,1,1,1,1,1]       => 0
[3,3,3,3]                 => 0
[3,3,3,2,1]               => 0
[3,3,3,1,1,1]             => 0
[3,3,2,2,2]               => 0
[3,3,2,2,1,1]             => 0
[3,3,2,1,1,1,1]           => 0
[3,3,1,1,1,1,1,1]         => 0
[3,2,2,2,2,1]             => 0
[3,2,2,2,1,1,1]           => 0
[3,2,2,1,1,1,1,1]         => 0
[3,2,1,1,1,1,1,1,1]       => 0
[3,1,1,1,1,1,1,1,1,1]     => 0
[2,2,2,2,2,2]             => 0
[2,2,2,2,2,1,1]           => 0
[2,2,2,2,1,1,1,1]         => 0
[2,2,2,1,1,1,1,1,1]       => 0
[2,2,1,1,1,1,1,1,1,1]     => 0
[2,1,1,1,1,1,1,1,1,1,1]   => 0
[1,1,1,1,1,1,1,1,1,1,1,1] => 0

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Created: Mar 17, 2018 at 14:34 by Martin Rubey

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Last Updated: Mar 17, 2018 at 14:34 by Martin Rubey