A square array of linear-factorial numbers, read by antidiagonals.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =1a(7) =3a(8) =6a(9) =6a(10) =1a(11) =4a(12) =10a(13) =24a(14) =24a(15) =1a(16) =5a(17) =14a(18) =42a(19) =120a(20) =120a(21) =1a(22) =6a(23) =18a(24) =60a(25) =216a(26) =720a(27) =720a(28) =1a(29) =7