a(n) = 441*n^2 - 394*n + 88.

Terms

a(0) =135a(1) =1064a(2) =2875a(3) =5568a(4) =9143a(5) =13600a(6) =18939a(7) =25160a(8) =32263a(9) =40248a(10) =49115a(11) =58864a(12) =69495a(13) =81008a(14) =93403a(15) =106680a(16) =120839a(17) =135880a(18) =151803a(19) =168608a(20) =186295a(21) =204864a(22) =224315a(23) =244648a(24) =265863a(25) =287960a(26) =310939a(27) =334800a(28) =359543a(29) =385168