Squares composed of digits {1,5,6}.

Terms

a(0) =1a(1) =16a(2) =1156a(3) =6561a(4) =111556a(5) =556516a(6) =6661561a(7) =11115556a(8) =165611161a(9) =1111155556a(10) =1566655561a(11) =6661661161a(12) =111111555556