a(n) = 576*n^2 - 24.

Terms

a(0) =552a(1) =2280a(2) =5160a(3) =9192a(4) =14376a(5) =20712a(6) =28200a(7) =36840a(8) =46632a(9) =57576a(10) =69672a(11) =82920a(12) =97320a(13) =112872a(14) =129576a(15) =147432a(16) =166440a(17) =186600a(18) =207912a(19) =230376a(20) =253992a(21) =278760a(22) =304680a(23) =331752a(24) =359976a(25) =389352a(26) =419880a(27) =451560a(28) =484392a(29) =518376