a(n) = (2*n - 9)*n^2.

Terms

a(0) =0a(1) =-7a(2) =-20a(3) =-27a(4) =-16a(5) =25a(6) =108a(7) =245a(8) =448a(9) =729a(10) =1100a(11) =1573a(12) =2160a(13) =2873a(14) =3724a(15) =4725a(16) =5888a(17) =7225a(18) =8748a(19) =10469a(20) =12400a(21) =14553a(22) =16940a(23) =19573a(24) =22464a(25) =25625a(26) =29068a(27) =32805a(28) =36848a(29) =41209