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%I #5 Mar 30 2012 18:38:57
%S 6,8,120,72,5040,1152,362880,28800,39916800,1036800,6227020800,
%T 50803200,1307674368000,3251404800,355687428096000,263363788800,
%U 121645100408832000,26336378880000,51090942171709440000
%N Order of the subgroup of the symmetric group S_n generated by the cycles (1,3) and (1,2,3,...,n).
%F If n is odd a(n) = n!, if n is even a(n) = 2 * ((n/2)!)^2 = 2 * n! / A000984(n/2) = 2 * A001044(n/2).
%Y Cf. A000984, A070734, A000142, A009445, A001044.
%K nonn,easy
%O 3,1
%A Sharon Sela (sharonsela(AT)hotmail.com), May 16 2002
%E More terms from _Benoit Cloitre_, May 20 2002
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