8000n - 6040.

Terms

a(0) =1960a(1) =9960a(2) =17960a(3) =25960a(4) =33960a(5) =41960a(6) =49960a(7) =57960a(8) =65960a(9) =73960a(10) =81960a(11) =89960a(12) =97960a(13) =105960a(14) =113960a(15) =121960a(16) =129960a(17) =137960a(18) =145960a(19) =153960a(20) =161960a(21) =169960a(22) =177960a(23) =185960a(24) =193960a(25) =201960a(26) =209960a(27) =217960a(28) =225960a(29) =233960