Triangle read by rows: T(n, k) (0 <= k <= n) = [x^k] x^n * n! * [t^n] x*(1 + t)/(x*exp(-t) - t).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =6a(5) =3a(6) =6a(7) =24a(8) =24a(9) =4a(10) =24a(11) =120a(12) =180a(13) =80a(14) =5a(15) =120a(16) =720a(17) =1440a(18) =1080a(19) =240a(20) =6a(21) =720a(22) =5040a(23) =12600a(24) =13440a(25) =5670a(26) =672a(27) =7a(28) =5040a(29) =40320