a(n) = 3*n^2 - 3*n + 2.

Terms

a(0) =2a(1) =2a(2) =8a(3) =20a(4) =38a(5) =62a(6) =92a(7) =128a(8) =170a(9) =218a(10) =272a(11) =332a(12) =398a(13) =470a(14) =548a(15) =632a(16) =722a(17) =818a(18) =920a(19) =1028a(20) =1142a(21) =1262a(22) =1388a(23) =1520a(24) =1658a(25) =1802a(26) =1952a(27) =2108a(28) =2270a(29) =2438