a(n) = 49*n^2 - 20*n + 2.

Terms

a(0) =31a(1) =158a(2) =383a(3) =706a(4) =1127a(5) =1646a(6) =2263a(7) =2978a(8) =3791a(9) =4702a(10) =5711a(11) =6818a(12) =8023a(13) =9326a(14) =10727a(15) =12226a(16) =13823a(17) =15518a(18) =17311a(19) =19202a(20) =21191a(21) =23278a(22) =25463a(23) =27746a(24) =30127a(25) =32606a(26) =35183a(27) =37858a(28) =40631a(29) =43502