Numbers k such that k and k^2 use only the digits 0, 3, 4, 7 and 8.

Terms

a(0) =0a(1) =88a(2) =878a(3) =880a(4) =8780a(5) =8800a(6) =87800a(7) =88000a(8) =878000a(9) =880000a(10) =8387078a(11) =8780000a(12) =8800000a(13) =83870780a(14) =87800000a(15) =88000000a(16) =838707800a(17) =878000000a(18) =880000000a(19) =8387078000a(20) =8780000000a(21) =8800000000a(22) =8833878448a(23) =83870780000a(24) =87774340088a(25) =87800000000a(26) =88000000000a(27) =88004400088a(28) =88338784480a(29) =838707800000