a(n) = 1089*n^2 - 33.

Terms

a(0) =1056a(1) =4323a(2) =9768a(3) =17391a(4) =27192a(5) =39171a(6) =53328a(7) =69663a(8) =88176a(9) =108867a(10) =131736a(11) =156783a(12) =184008a(13) =213411a(14) =244992a(15) =278751a(16) =314688a(17) =352803a(18) =393096a(19) =435567a(20) =480216a(21) =527043a(22) =576048a(23) =627231a(24) =680592a(25) =736131a(26) =793848a(27) =853743a(28) =915816a(29) =980067