a(n) = 12*n^2 + 4*n + 1.

Terms

a(0) =1a(1) =17a(2) =57a(3) =121a(4) =209a(5) =321a(6) =457a(7) =617a(8) =801a(9) =1009a(10) =1241a(11) =1497a(12) =1777a(13) =2081a(14) =2409a(15) =2761a(16) =3137a(17) =3537a(18) =3961a(19) =4409a(20) =4881a(21) =5377a(22) =5897a(23) =6441a(24) =7009a(25) =7601a(26) =8217a(27) =8857a(28) =9521a(29) =10209