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

Terms

a(0) =5a(1) =6a(2) =25a(3) =26a(4) =75a(5) =76a(6) =235a(7) =256a(8) =275a(9) =525a(10) =526a(11) =725a(12) =2525a(13) =2576a(14) =5256a(15) =5725a(16) =5765a(17) =7325a(18) =7525a(19) =7535a(20) =23566a(21) =27525a(22) =27665a(23) =52275a(24) =56765a(25) =57665a(26) =57666a(27) =57756a(28) =72275a(29) =72335