a(n) = v(n+1)/(8*v(n)), where v=A203524.

A203525

a(n) = v(n+1)/(8*v(n)), where v=A203524.

Terms

    a(0) =1a(1) =15a(2) =504a(3) =17280a(4) =1108800a(5) =59304960a(6) =5613753600a(7) =944393748480

External references