a(n) = 1600*n^2 + 40.

Terms

a(0) =1640a(1) =6440a(2) =14440a(3) =25640a(4) =40040a(5) =57640a(6) =78440a(7) =102440a(8) =129640a(9) =160040a(10) =193640a(11) =230440a(12) =270440a(13) =313640a(14) =360040a(15) =409640a(16) =462440a(17) =518440a(18) =577640a(19) =640040a(20) =705640a(21) =774440a(22) =846440a(23) =921640a(24) =1000040a(25) =1081640a(26) =1166440a(27) =1254440a(28) =1345640a(29) =1440040