Triangle read by rows: number of permutation trees of power n and height <= k + 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =1a(5) =5a(6) =6a(7) =1a(8) =15a(9) =23a(10) =24a(11) =1a(12) =52a(13) =106a(14) =119a(15) =120a(16) =1a(17) =203a(18) =568a(19) =700a(20) =719a(21) =720a(22) =1a(23) =877a(24) =3459a(25) =4748a(26) =5013a(27) =5039a(28) =5040a(29) =1