a(n) = 6*n^2 - 10*n + 5.

Terms

a(0) =1a(1) =9a(2) =29a(3) =61a(4) =105a(5) =161a(6) =229a(7) =309a(8) =401a(9) =505a(10) =621a(11) =749a(12) =889a(13) =1041a(14) =1205a(15) =1381a(16) =1569a(17) =1769a(18) =1981a(19) =2205a(20) =2441a(21) =2689a(22) =2949a(23) =3221a(24) =3505a(25) =3801a(26) =4109a(27) =4429a(28) =4761a(29) =5105