Numbers k such that k and k^2 use only the digits 0, 2, 5, 6 and 7.

Terms

a(0) =0a(1) =5a(2) =25a(3) =26a(4) =50a(5) =75a(6) =76a(7) =225a(8) =250a(9) =255a(10) =260a(11) =265a(12) =266a(13) =275a(14) =500a(15) =505a(16) =525a(17) =526a(18) =725a(19) =726a(20) =750a(21) =755a(22) =760a(23) =775a(24) =2250a(25) =2500a(26) =2505a(27) =2550a(28) =2600a(29) =2650