a(n) = 2*n^2 + 9*n - 5.

Terms

a(0) =6a(1) =21a(2) =40a(3) =63a(4) =90a(5) =121a(6) =156a(7) =195a(8) =238a(9) =285a(10) =336a(11) =391a(12) =450a(13) =513a(14) =580a(15) =651a(16) =726a(17) =805a(18) =888a(19) =975a(20) =1066a(21) =1161a(22) =1260a(23) =1363a(24) =1470a(25) =1581a(26) =1696a(27) =1815a(28) =1938a(29) =2065