Left 3-step factorial (n,-3)!: a(n) = (-1)^n * A008544(n).

A133480

Left 3-step factorial (n,-3)!: a(n) = (-1)^n * A008544(n).

Terms

    a(0) =1a(1) =-2a(2) =10a(3) =-80a(4) =880a(5) =-12320a(6) =209440a(7) =-4188800a(8) =96342400a(9) =-2504902400a(10) =72642169600

External references