a(n) = A002952(n) + A002953(n).

Terms

a(0) =240a(1) =2400a(2) =40320a(3) =72576a(4) =94080a(5) =120960a(6) =141120a(7) =311040a(8) =403200a(9) =483840a(10) =483840a(11) =725760a(12) =673920a(13) =1010880a(14) =1209600a(15) =1497600a(16) =1411200a(17) =1612800a(18) =1747200a(19) =2246400a(20) =2177280a(21) =2371200a(22) =2449440a(23) =2419200a(24) =2620800a(25) =2903040a(26) =3144960a(27) =3110400