a(0)=1, a(1)=0, a(n) = 4*n*(n-1)*(a(n-1) + 2*(n-1)*a(n-2)).

A189849

a(0)=1, a(1)=0, a(n) = 4*n*(n-1)*(a(n-1) + 2*(n-1)*a(n-2)).

Terms

    a(0) =1a(1) =0a(2) =16a(3) =384a(4) =23040a(5) =2088960a(6) =278323200a(7) =50969640960

External references