Numbers k such that k and k^2 use only the digits 0, 2, 5, 6 and 9.

Terms

a(0) =0a(1) =5a(2) =25a(3) =50a(4) =95a(5) =225a(6) =250a(7) =255a(8) =500a(9) =505a(10) =950a(11) =995a(12) =2250a(13) =2500a(14) =2550a(15) =5000a(16) =5005a(17) =5025a(18) =5050a(19) =5095a(20) =9500a(21) =9605a(22) =9950a(23) =9995a(24) =22500a(25) =22925a(26) =25000a(27) =25005a(28) =25025a(29) =25500