a(n) = 4*n*(1 + 45*n + 620*n^2).

Terms

a(0) =2664a(1) =20568a(2) =68592a(3) =161616a(4) =314520a(5) =542184a(6) =859488a(7) =1281312a(8) =1822536a(9) =2498040a(10) =3322704a(11) =4311408a(12) =5479032a(13) =6840456a(14) =8410560a(15) =10204224a(16) =12236328a(17) =14521752a(18) =17075376a(19) =19912080a(20) =23046744a(21) =26494248a(22) =30269472a(23) =34387296a(24) =38862600a(25) =43710264a(26) =48945168a(27) =54582192a(28) =60636216