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A060249
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Size of the automorphism group of the symmetric group S_n.
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3
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1, 1, 6, 24, 120, 1440, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 87178291200, 1307674368000, 20922789888000, 355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000
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OFFSET
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1,3
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COMMENTS
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For all n except n=2 and n=6, Aut(S_n) is S_n itself, i.e. S_n has no outer automorphisms. Aut(S_2) is trivial and Aut(S_6) is of order 2*|S_6| = 1440 - there is an outer involution.
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LINKS
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FORMULA
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a(n) = n! except for n=2 and 6.
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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Ola Veshta (olaveshta(AT)my-deja.com), Mar 22 2001
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EXTENSIONS
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STATUS
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approved
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