a(n) = 12*n^2 + 18*n.

Terms

a(0) =0a(1) =30a(2) =84a(3) =162a(4) =264a(5) =390a(6) =540a(7) =714a(8) =912a(9) =1134a(10) =1380a(11) =1650a(12) =1944a(13) =2262a(14) =2604a(15) =2970a(16) =3360a(17) =3774a(18) =4212a(19) =4674a(20) =5160a(21) =5670a(22) =6204a(23) =6762a(24) =7344a(25) =7950a(26) =8580a(27) =9234a(28) =9912a(29) =10614