a(n) = 8*n^2 - 2*n + 1.

Terms

a(0) =1a(1) =7a(2) =29a(3) =67a(4) =121a(5) =191a(6) =277a(7) =379a(8) =497a(9) =631a(10) =781a(11) =947a(12) =1129a(13) =1327a(14) =1541a(15) =1771a(16) =2017a(17) =2279a(18) =2557a(19) =2851a(20) =3161a(21) =3487a(22) =3829a(23) =4187a(24) =4561a(25) =4951a(26) =5357a(27) =5779a(28) =6217a(29) =6671