Triangle read by rows: A007318 * A136717.

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =6a(5) =4a(6) =1a(7) =12a(8) =24a(9) =12a(10) =1a(11) =20a(12) =72a(13) =120a(14) =48a(15) =1a(16) =30a(17) =160a(18) =552a(19) =696a(20) =192a(21) =1a(22) =42a(23) =300a(24) =1752a(25) =4416a(26) =4272a(27) =960a(28) =1a(29) =56