a(n) is the (1,2)-entry of the n-th power of the 2 X 2 matrix [0,1;n-1,2(n-1)].

A109517

a(n) is the (1,2)-entry of the n-th power of the 2 X 2 matrix [0,1;n-1,2(n-1)].

Terms

    a(0) =1a(1) =2a(2) =18a(3) =252a(4) =4880a(5) =120750a(6) =3639384a(7) =129365880a(8) =5298720768a(9) =245738908890

External references