a(n) = n*floor(n/2)^2.

Terms

a(0) =0a(1) =0a(2) =2a(3) =3a(4) =16a(5) =20a(6) =54a(7) =63a(8) =128a(9) =144a(10) =250a(11) =275a(12) =432a(13) =468a(14) =686a(15) =735a(16) =1024a(17) =1088a(18) =1458a(19) =1539a(20) =2000a(21) =2100a(22) =2662a(23) =2783a(24) =3456a(25) =3600a(26) =4394a(27) =4563a(28) =5488a(29) =5684