**Sum ((-1)^(i+1)*binomial(n,i)*2^i*(2*n-1)!,i=1..n) for n odd.**

*2, 240, 725760, 12454041600, 711374856192000, 102181884343418880000*

*1 seqfan posts*

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

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