a(n) = 9*n^2 + 18*n + 7.

Terms

a(0) =7a(1) =34a(2) =79a(3) =142a(4) =223a(5) =322a(6) =439a(7) =574a(8) =727a(9) =898a(10) =1087a(11) =1294a(12) =1519a(13) =1762a(14) =2023a(15) =2302a(16) =2599a(17) =2914a(18) =3247a(19) =3598a(20) =3967a(21) =4354a(22) =4759a(23) =5182a(24) =5623a(25) =6082a(26) =6559a(27) =7054a(28) =7567a(29) =8098