Numbers k such that k and k^2 use only the digits 1, 3, 5, 6 and 7.

Terms

a(0) =1a(1) =6a(2) =56a(3) =76a(4) =131a(5) =576a(6) =756a(7) =1156a(8) =1331a(9) =3656a(10) =5756a(11) =7166a(12) =11731a(13) =13331a(14) =57716a(15) =57756a(16) =75576a(17) =117331a(18) =133331a(19) =337131a(20) =371156a(21) =577716a(22) =611156a(23) =717756a(24) =731666a(25) =755756a(26) =1333331a(27) =1771331a(28) =3336731a(29) =3367131