Triangle read by rows: T(n,k) = n*T(n-1,k-1) + k*T(n-1,k) starting with T(0,0)=1.

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =1a(5) =2a(6) =0a(7) =1a(8) =7a(9) =6a(10) =0a(11) =1a(12) =18a(13) =46a(14) =24a(15) =0a(16) =1a(17) =41a(18) =228a(19) =326a(20) =120a(21) =0a(22) =1a(23) =88a(24) =930a(25) =2672a(26) =2556a(27) =720a(28) =0a(29) =1