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Search: id:A070734
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| A070734 |
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Order of the subgroup of the symmetric group S_n generated by the cycles (1,2,3) and (1,2,3,...,n). |
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+0
3
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| 3, 24, 60, 720, 2520, 40320, 181440, 3628800, 19958400, 479001600, 3113510400, 87178291200, 653837184000, 20922789888000, 177843714048000, 6402373705728000, 60822550204416000, 2432902008176640000
(list; graph; listen)
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OFFSET
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3,1
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FORMULA
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For odd n: a(n) = n!/2; for even n: a(n) = n!.
a(n) = 1/4*(3+(-1)^n)*n! - Benoit Cloitre (benoit7848c(AT)orange.fr), May 18 2002
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MATHEMATICA
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f[n_] := If[ EvenQ[n], n!, n!/2]; Table[ f[n], {n, 3, 24}].
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PROGRAM
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(PARI) for(n=3, 20, print1((3+(-1)^n)/4*n!, ", "))
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CROSSREFS
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Cf. A000142, A001710.
Sequence in context: A106217 A160665 A101008 this_sequence A009113 A152751 A162654
Adjacent sequences: A070731 A070732 A070733 this_sequence A070735 A070736 A070737
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KEYWORD
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nonn,easy
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AUTHOR
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Sharon Sela (sharonsela(AT)hotmail.com), May 14 2002
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EXTENSIONS
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More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), May 18 2002
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