Triangle read by rows: number of permutation trees of power n and height <= n - k.

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =6a(5) =5a(6) =1a(7) =24a(8) =23a(9) =9a(10) =1a(11) =120a(12) =119a(13) =68a(14) =14a(15) =1a(16) =720a(17) =719a(18) =517a(19) =152a(20) =20a(21) =1a(22) =5040a(23) =5039a(24) =4163a(25) =1581a(26) =292a(27) =27a(28) =1a(29) =40320