A344857(2*n).

Terms

a(0) =0a(1) =4a(2) =42a(3) =176a(4) =540a(5) =1152a(6) =2534a(7) =4608a(8) =6984a(9) =12580a(10) =19250a(11) =26016a(12) =39988a(13) =55076a(14) =63570a(15) =97920a(16) =127024a(17) =155088a(18) =203946a(19) =253360a(20) =289044a(21) =378884a(22) =456918a(23) =528672a(24) =648200a(25) =763620a(26) =869022a(27) =1040368a(28) =1204196a(29) =1318440