a(n) = A181089(2*n+1,n)/(n+2).

A181088

a(n) = A181089(2*n+1,n)/(n+2).

Terms

    a(0) =1a(1) =-4a(2) =-40a(3) =672a(4) =8064a(5) =-253440a(6) =-3294720a(7) =153753600a(8) =2091048960a(9) =-130025226240

External references