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

Terms

a(0) =25a(1) =121a(2) =289a(3) =529a(4) =841a(5) =1225a(6) =1681a(7) =2209a(8) =2809a(9) =3481a(10) =4225a(11) =5041a(12) =5929a(13) =6889a(14) =7921a(15) =9025a(16) =10201a(17) =11449a(18) =12769a(19) =14161a(20) =15625a(21) =17161a(22) =18769a(23) =20449a(24) =22201a(25) =24025a(26) =25921a(27) =27889a(28) =29929a(29) =32041