Numbers k such that k and k^2 use only the digits 2, 3, 7, 8 and 9.

Terms

a(0) =3a(1) =27a(2) =2973a(3) =2983a(4) =88223a(5) =88277a(6) =298327a(7) =299833a(8) =993923a(9) =2978923a(10) =9893323a(11) =9939277a(12) =27978277a(13) =28773233a(14) =28798233a(15) =28978923a(16) =29729327a(17) =29828223a(18) =29983327a(19) =29998333a(20) =88283233a(21) =93989323a(22) =98887733a(23) =98893323a(24) =287989233a(25) =289799827a(26) =297293327a(27) =298978223a(28) =887299233a(29) =893293277