Numbers k such that k and k^2 use only the digits 1, 2, 5, 6 and 9.

Terms

a(0) =1a(1) =5a(2) =11a(3) =15a(4) =16a(5) =25a(6) =96a(7) =125a(8) =161a(9) =511a(10) =515a(11) =516a(12) =1119a(13) =1125a(14) =1515a(15) =1619a(16) =2261a(17) =5125a(18) =9619a(19) =9961a(20) =12296a(21) =12511a(22) =12515a(23) =16215a(24) =16296a(25) =22619a(26) =22925a(27) =25525a(28) =25596a(29) =51211