Numbers k such that k and k^2 use only the digits 1, 3, 5, 6 and 8.

Terms

a(0) =1a(1) =6a(2) =56a(3) =81a(4) =816a(5) =1156a(6) =1881a(7) =3656a(8) =8131a(9) =8166a(10) =36316a(11) =81556a(12) =116881a(13) =188556a(14) =581666a(15) =813381a(16) =1163566a(17) =1168581a(18) =1366881a(19) =1888566a(20) =5613656a(21) =11555881a(22) =11668381a(23) =13551316a(24) =18313556a(25) =18353656a(26) =36316156a(27) =36556331a(28) =56138816a(29) =56156331