**a(n) = 2(m!)^2 for n = 2m and m!(m+1)! for n = 2m+1.**

*2, 1, 2, 2, 8, 12, 72, 144, 1152, 2880, 28800, 86400, 1036800, 3628800, 50803200*

*2 seqfan posts*

Index of A-numbers in seqfan: by ascending order by month by frequency by keyword

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