Squares composed of digits {4,6,9}.

Terms

a(0) =4a(1) =9a(2) =49a(3) =64a(4) =44944a(5) =69696a(6) =4999696a(7) =9696996a(8) =9966649a(9) =999444996a(10) =4649466969a(11) =64944444964