This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A257086 #11 Apr 19 2015 00:23:34
%S A257086 0,1,2,5,10,11,12,15,20,21,32,35,45,50,55,100,101,102,105,110,111,112,
%T A257086 115,120,145,150,152,155,200,201,205,210,211,235,320,321,332,335,350,
%U A257086 351,450,451,452,500,501,502,505,550,1000,1001,1002,1005,1010,1011,1012,1015,1020,1021,1050,1055,1100
%N A257086 Numbers n such that the decimal expansions of both n and n^2 only use the digits 0..5.
%H A257086 Danny Rorabaugh, <a href="/A257086/b257086.txt">Table of n, a(n) for n = 1..5000</a>
%e A257086 115 is in the list because 115 and 115^2 = 13225 do not use the digits 6, 7, 8, or 9.
%e A257086 121 is not in the list because 121^2 = 14641 uses the digit 6.
%e A257086 149 is not in the list because it uses the digit 9 (even though 149^2 = 22201 would be okay).
%t A257086 Select[Range@ 1100, Total@ Take[DigitCount[#], {6, 9}] == 0 && Total@ Take[DigitCount[#^2], {6, 9}] == 0 &] (* _Michael De Vlieger_, Apr 17 2015 *)
%Y A257086 Cf. A178501 (0..1), A136808(0..2), A136809(0..3), A136810 (0..4), A257085 (0..6).
%Y A257086 Cf. A136817, A256631.
%K A257086 nonn,easy,base
%O A257086 1,3
%A A257086 _Danny Rorabaugh_, Apr 15 2015