a(n) = 9*n^2 - 13*n + 5.

Terms

a(0) =1a(1) =15a(2) =47a(3) =97a(4) =165a(5) =251a(6) =355a(7) =477a(8) =617a(9) =775a(10) =951a(11) =1145a(12) =1357a(13) =1587a(14) =1835a(15) =2101a(16) =2385a(17) =2687a(18) =3007a(19) =3345a(20) =3701a(21) =4075a(22) =4467a(23) =4877a(24) =5305a(25) =5751a(26) =6215a(27) =6697a(28) =7197a(29) =7715