A257086 - OEIS

%I #11 Apr 19 2015 00:23:34

%S 0,1,2,5,10,11,12,15,20,21,32,35,45,50,55,100,101,102,105,110,111,112,

%T 115,120,145,150,152,155,200,201,205,210,211,235,320,321,332,335,350,

%U 351,450,451,452,500,501,502,505,550,1000,1001,1002,1005,1010,1011,1012,1015,1020,1021,1050,1055,1100

%N Numbers n such that the decimal expansions of both n and n^2 only use the digits 0..5.

%H Danny Rorabaugh, <a href="/A257086/b257086.txt">Table of n, a(n) for n = 1..5000</a>

%e 115 is in the list because 115 and 115^2 = 13225 do not use the digits 6, 7, 8, or 9.

%e 121 is not in the list because 121^2 = 14641 uses the digit 6.

%e 149 is not in the list because it uses the digit 9 (even though 149^2 = 22201 would be okay).

%t Select[Range@ 1100, Total@ Take[DigitCount[#], {6, 9}] == 0 && Total@ Take[DigitCount[#^2], {6, 9}] == 0 &] (* _Michael De Vlieger_, Apr 17 2015 *)

%Y Cf. A178501 (0..1), A136808(0..2), A136809(0..3), A136810 (0..4), A257085 (0..6).

%Y Cf. A136817, A256631.

%K nonn,easy,base

%O 1,3

%A _Danny Rorabaugh_, Apr 15 2015