Triangular array A066667 or A008297 unsigned and transposed.

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =6a(5) =6a(6) =1a(7) =12a(8) =36a(9) =24a(10) =1a(11) =20a(12) =120a(13) =240a(14) =120a(15) =1a(16) =30a(17) =300a(18) =1200a(19) =1800a(20) =720a(21) =1a(22) =42a(23) =630a(24) =4200a(25) =12600a(26) =15120a(27) =5040a(28) =1a(29) =56