a(n) = 14*n^2 - 4*n.

Terms

a(0) =0a(1) =10a(2) =48a(3) =114a(4) =208a(5) =330a(6) =480a(7) =658a(8) =864a(9) =1098a(10) =1360a(11) =1650a(12) =1968a(13) =2314a(14) =2688a(15) =3090a(16) =3520a(17) =3978a(18) =4464a(19) =4978a(20) =5520a(21) =6090a(22) =6688a(23) =7314a(24) =7968a(25) =8650a(26) =9360a(27) =10098a(28) =10864a(29) =11658