Numbers k such that k and k^2 use only the digits 0, 2, 3, 5 and 7.

Terms

a(0) =0a(1) =5a(2) =50a(3) =55a(4) =235a(5) =500a(6) =505a(7) =550a(8) =755a(9) =2350a(10) =5000a(11) =5005a(12) =5050a(13) =5055a(14) =5500a(15) =5505a(16) =7550a(17) =23500a(18) =50000a(19) =50005a(20) =50050a(21) =50055a(22) =50235a(23) =50500a(24) =50505a(25) =50550a(26) =55000a(27) =55005a(28) =55050a(29) =57055