Multi-level factorials: triangle with a(n,k)=a(n-1,k-1)*a(n-1,k) but with a(n,1)=n and a(n,n)=1.

Terms

a(0) =1a(1) =2a(2) =1a(3) =3a(4) =2a(5) =1a(6) =4a(7) =6a(8) =2a(9) =1a(10) =5a(11) =24a(12) =12a(13) =2a(14) =1a(15) =6a(16) =120a(17) =288a(18) =24a(19) =2a(20) =1a(21) =7a(22) =720a(23) =34560a(24) =6912a(25) =48a(26) =2a(27) =1a(28) =8a(29) =5040