Squares which are concatenation of two positive squares with possible intervening zeros.

Terms

a(0) =49a(1) =169a(2) =361a(3) =1225a(4) =1444a(5) =1681a(6) =3249a(7) =4225a(8) =4900a(9) =9025a(10) =15625a(11) =16900a(12) =36100a(13) =42025a(14) =49729a(15) =64009a(16) =81225a(17) =93025a(18) =105625a(19) =122500a(20) =144400a(21) =168100a(22) =225625a(23) =237169a(24) =256036a(25) =324900a(26) =422500a(27) =490000a(28) =519841a(29) =576081