a(n) = 6*n^2 + 10*n + 5.

Terms

a(0) =5a(1) =21a(2) =49a(3) =89a(4) =141a(5) =205a(6) =281a(7) =369a(8) =469a(9) =581a(10) =705a(11) =841a(12) =989a(13) =1149a(14) =1321a(15) =1505a(16) =1701a(17) =1909a(18) =2129a(19) =2361a(20) =2605a(21) =2861a(22) =3129a(23) =3409a(24) =3701a(25) =4005a(26) =4321a(27) =4649a(28) =4989a(29) =5341