Numbers k such that k and k^2 use only the digits 1, 2, 5, 8 and 9.

Terms

a(0) =1a(1) =5a(2) =9a(3) =11a(4) =15a(5) =91a(6) =159a(7) =285a(8) =911a(9) =1515a(10) =1585a(11) =2285a(12) =29859a(13) =92511a(14) =95911a(15) =111891a(16) =285515a(17) =2992589a(18) =9225591a(19) =9228159a(20) =9991289a(21) =15891891a(22) =22991285a(23) =29819891a(24) =99291585a(25) =99295515a(26) =111889289a(27) =151189285a(28) =151189589a(29) =229825989