8 times octagonal numbers: 8*n*(3*n-2).

Terms

a(0) =0a(1) =8a(2) =64a(3) =168a(4) =320a(5) =520a(6) =768a(7) =1064a(8) =1408a(9) =1800a(10) =2240a(11) =2728a(12) =3264a(13) =3848a(14) =4480a(15) =5160a(16) =5888a(17) =6664a(18) =7488a(19) =8360a(20) =9280a(21) =10248a(22) =11264a(23) =12328a(24) =13440a(25) =14600a(26) =15808a(27) =17064a(28) =18368a(29) =19720