Fourth column of triangle A075499.

A075907

Fourth column of triangle A075499.

Terms

    a(0) =1a(1) =40a(2) =1040a(3) =22400a(4) =435456a(5) =7956480a(6) =139694080a(7) =2387968000a(8) =40075329536a(9) =663887544320

External references