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A072169
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Commuting permutations: number of ordered triples f, g, h in Symm(n) which all commute.
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2
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OFFSET
| 1,2
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REFERENCES
| Computed by John McKay, Sep 06 2003
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PROG
| (MAGMA) for n in {1 .. 5} do G := SymmetricGroup(n); t1 := 0; for g in G do for h in G do for i in G do if g*h eq h*g and g*i eq i*g and h*i eq i*h then t1 := t1+1; end if; end for; end for; end for; n, t1; end for;
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CROSSREFS
| Cf. A079860, A053529.
Sequence in context: A013186 A165506 A165748 * A052575 A108214 A181276
Adjacent sequences: A072166 A072167 A072168 * A072170 A072171 A072172
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KEYWORD
| nonn,more
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Sep 06 2003
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