a(n) = 6*n^2 + 8*n + 1.

Terms

a(0) =1a(1) =15a(2) =41a(3) =79a(4) =129a(5) =191a(6) =265a(7) =351a(8) =449a(9) =559a(10) =681a(11) =815a(12) =961a(13) =1119a(14) =1289a(15) =1471a(16) =1665a(17) =1871a(18) =2089a(19) =2319a(20) =2561a(21) =2815a(22) =3081a(23) =3359a(24) =3649a(25) =3951a(26) =4265a(27) =4591a(28) =4929a(29) =5279