a(n) = 7*n^2 - 5*n + 1.

Terms

a(0) =1a(1) =3a(2) =19a(3) =49a(4) =93a(5) =151a(6) =223a(7) =309a(8) =409a(9) =523a(10) =651a(11) =793a(12) =949a(13) =1119a(14) =1303a(15) =1501a(16) =1713a(17) =1939a(18) =2179a(19) =2433a(20) =2701a(21) =2983a(22) =3279a(23) =3589a(24) =3913a(25) =4251a(26) =4603a(27) =4969a(28) =5349a(29) =5743