a(n) = 12*n^2 - 8*n + 1.

Terms

a(0) =1a(1) =5a(2) =33a(3) =85a(4) =161a(5) =261a(6) =385a(7) =533a(8) =705a(9) =901a(10) =1121a(11) =1365a(12) =1633a(13) =1925a(14) =2241a(15) =2581a(16) =2945a(17) =3333a(18) =3745a(19) =4181a(20) =4641a(21) =5125a(22) =5633a(23) =6165a(24) =6721a(25) =7301a(26) =7905a(27) =8533a(28) =9185a(29) =9861