a(n) = 400*n^2 - 2*n.

Terms

a(0) =398a(1) =1596a(2) =3594a(3) =6392a(4) =9990a(5) =14388a(6) =19586a(7) =25584a(8) =32382a(9) =39980a(10) =48378a(11) =57576a(12) =67574a(13) =78372a(14) =89970a(15) =102368a(16) =115566a(17) =129564a(18) =144362a(19) =159960a(20) =176358a(21) =193556a(22) =211554a(23) =230352a(24) =249950a(25) =270348a(26) =291546a(27) =313544a(28) =336342a(29) =359940