a(n) = 68*n^2 + 1.

Terms

a(0) =1a(1) =69a(2) =273a(3) =613a(4) =1089a(5) =1701a(6) =2449a(7) =3333a(8) =4353a(9) =5509a(10) =6801a(11) =8229a(12) =9793a(13) =11493a(14) =13329a(15) =15301a(16) =17409a(17) =19653a(18) =22033a(19) =24549a(20) =27201a(21) =29989a(22) =32913a(23) =35973a(24) =39169a(25) =42501a(26) =45969a(27) =49573a(28) =53313a(29) =57189