a(n) = (3*n+1)*(3*n+4).

Terms

a(0) =4a(1) =28a(2) =70a(3) =130a(4) =208a(5) =304a(6) =418a(7) =550a(8) =700a(9) =868a(10) =1054a(11) =1258a(12) =1480a(13) =1720a(14) =1978a(15) =2254a(16) =2548a(17) =2860a(18) =3190a(19) =3538a(20) =3904a(21) =4288a(22) =4690a(23) =5110a(24) =5548a(25) =6004a(26) =6478a(27) =6970a(28) =7480a(29) =8008