a(n) = (7*n + 3)^2.

Terms

a(0) =9a(1) =100a(2) =289a(3) =576a(4) =961a(5) =1444a(6) =2025a(7) =2704a(8) =3481a(9) =4356a(10) =5329a(11) =6400a(12) =7569a(13) =8836a(14) =10201a(15) =11664a(16) =13225a(17) =14884a(18) =16641a(19) =18496a(20) =20449a(21) =22500a(22) =24649a(23) =26896a(24) =29241a(25) =31684a(26) =34225a(27) =36864a(28) =39601a(29) =42436