a(n) = (9*n + 8)^2.

Terms

a(0) =64a(1) =289a(2) =676a(3) =1225a(4) =1936a(5) =2809a(6) =3844a(7) =5041a(8) =6400a(9) =7921a(10) =9604a(11) =11449a(12) =13456a(13) =15625a(14) =17956a(15) =20449a(16) =23104a(17) =25921a(18) =28900a(19) =32041a(20) =35344a(21) =38809a(22) =42436a(23) =46225a(24) =50176a(25) =54289a(26) =58564a(27) =63001a(28) =67600a(29) =72361