a(n) = 4*(4 + 9*n^2 + 15*n).

Terms

a(0) =16a(1) =112a(2) =280a(3) =520a(4) =832a(5) =1216a(6) =1672a(7) =2200a(8) =2800a(9) =3472a(10) =4216a(11) =5032a(12) =5920a(13) =6880a(14) =7912a(15) =9016a(16) =10192a(17) =11440a(18) =12760a(19) =14152a(20) =15616a(21) =17152a(22) =18760a(23) =20440a(24) =22192a(25) =24016a(26) =25912a(27) =27880a(28) =29920a(29) =32032