Duplicate of A073841.

Terms

a(0) =4a(1) =12a(2) =24a(3) =360a(4) =360a(5) =2520a(6) =5040a(7) =5040a(8) =5040a(9) =55440a(10) =55440a(11) =3603600a(12) =10810800a(13) =10810800a(14) =21621600a(15) =367567200a(16) =367567200a(17) =6983776800a(18) =6983776800a(19) =6983776800a(20) =6983776800a(21) =160626866400a(22) =160626866400