a(n) = 6*n^2.

Terms

a(0) =0a(1) =6a(2) =24a(3) =54a(4) =96a(5) =150a(6) =216a(7) =294a(8) =384a(9) =486a(10) =600a(11) =726a(12) =864a(13) =1014a(14) =1176a(15) =1350a(16) =1536a(17) =1734a(18) =1944a(19) =2166a(20) =2400a(21) =2646a(22) =2904a(23) =3174a(24) =3456a(25) =3750a(26) =4056a(27) =4374a(28) =4704a(29) =5046