Triangle with a(n,n)=1, a(n,k)=(n-1)*a(n-1,k)+a(n-2,k) for n>k.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =3a(8) =2a(9) =1a(10) =7a(11) =10a(12) =7a(13) =3a(14) =1a(15) =30a(16) =43a(17) =30a(18) =13a(19) =4a(20) =1a(21) =157a(22) =225a(23) =157a(24) =68a(25) =21a(26) =5a(27) =1a(28) =972a(29) =1393