a(n) = 6*(24*n - 1).

Terms

a(0) =138a(1) =282a(2) =426a(3) =570a(4) =714a(5) =858a(6) =1002a(7) =1146a(8) =1290a(9) =1434a(10) =1578a(11) =1722a(12) =1866a(13) =2010a(14) =2154a(15) =2298a(16) =2442a(17) =2586a(18) =2730a(19) =2874a(20) =3018a(21) =3162a(22) =3306a(23) =3450a(24) =3594a(25) =3738a(26) =3882a(27) =4026a(28) =4170a(29) =4314