a(n) = (7*n + 3)*(7*n + 4).

Terms

a(0) =12a(1) =110a(2) =306a(3) =600a(4) =992a(5) =1482a(6) =2070a(7) =2756a(8) =3540a(9) =4422a(10) =5402a(11) =6480a(12) =7656a(13) =8930a(14) =10302a(15) =11772a(16) =13340a(17) =15006a(18) =16770a(19) =18632a(20) =20592a(21) =22650a(22) =24806a(23) =27060a(24) =29412a(25) =31862a(26) =34410a(27) =37056a(28) =39800a(29) =42642