Numbers k such that k and k^2 use only the digits 1, 2, 3, 8 and 9.

Terms

a(0) =1a(1) =3a(2) =9a(3) =11a(4) =91a(5) =111a(6) =139a(7) =911a(8) =1389a(9) =1823a(10) =1839a(11) =1983a(12) =2983a(13) =9123a(14) =18391a(15) =31339a(16) =93989a(17) =181339a(18) =199823a(19) =299823a(20) =313339a(21) =313391a(22) =913139a(23) =939889a(24) =1811983a(25) =1813339a(26) =1983233a(27) =2883123a(28) =2981339a(29) =2983139