a(n) = n*a(n-1) + (n-5)*a(n-2).

Terms

a(0) =0a(1) =1a(2) =5a(3) =31a(4) =227a(5) =1909a(6) =18089a(7) =190435a(8) =2203319a(9) =27772873a(10) =378673901a(11) =5551390471a(12) =87057596075