8 times triangular numbers: a(n) = 4*n*(n+1).

Terms

a(0) =0a(1) =8a(2) =24a(3) =48a(4) =80a(5) =120a(6) =168a(7) =224a(8) =288a(9) =360a(10) =440a(11) =528a(12) =624a(13) =728a(14) =840a(15) =960a(16) =1088a(17) =1224a(18) =1368a(19) =1520a(20) =1680a(21) =1848a(22) =2024a(23) =2208a(24) =2400a(25) =2600a(26) =2808a(27) =3024a(28) =3248a(29) =3480