a(n) = 8*n^2 - 4*n + 1.

Terms

a(0) =1a(1) =5a(2) =25a(3) =61a(4) =113a(5) =181a(6) =265a(7) =365a(8) =481a(9) =613a(10) =761a(11) =925a(12) =1105a(13) =1301a(14) =1513a(15) =1741a(16) =1985a(17) =2245a(18) =2521a(19) =2813a(20) =3121a(21) =3445a(22) =3785a(23) =4141a(24) =4513a(25) =4901a(26) =5305a(27) =5725a(28) =6161a(29) =6613