a(n) = 16*n^2 + 2*n + 1.

Terms

a(0) =1a(1) =19a(2) =69a(3) =151a(4) =265a(5) =411a(6) =589a(7) =799a(8) =1041a(9) =1315a(10) =1621a(11) =1959a(12) =2329a(13) =2731a(14) =3165a(15) =3631a(16) =4129a(17) =4659a(18) =5221a(19) =5815a(20) =6441a(21) =7099a(22) =7789a(23) =8511a(24) =9265a(25) =10051a(26) =10869a(27) =11719a(28) =12601a(29) =13515