A257086 Numbers n such that the decimal expansions of both n and n^2 only use the digits 0..5.

0, 1, 2, 5, 10, 11, 12, 15, 20, 21, 32, 35, 45, 50, 55, 100, 101, 102, 105, 110, 111, 112, 115, 120, 145, 150, 152, 155, 200, 201, 205, 210, 211, 235, 320, 321, 332, 335, 350, 351, 450, 451, 452, 500, 501, 502, 505, 550, 1000, 1001, 1002, 1005, 1010, 1011, 1012, 1015, 1020, 1021, 1050, 1055, 1100

Offset

1,3

Links

Danny Rorabaugh, Table of n, a(n) for n = 1..5000

Example

115 is in the list because 115 and 115^2 = 13225 do not use the digits 6, 7, 8, or 9.
121 is not in the list because 121^2 = 14641 uses the digit 6.
149 is not in the list because it uses the digit 9 (even though 149^2 = 22201 would be okay).

Mathematica

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

Crossrefs

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

Cf. A136817, A256631.

Sequence in context: A123466 A144793 A140707 * A136817 A140180 A175324

Adjacent sequences: A257083 A257084 A257085 * A257087 A257088 A257089

Keyword

nonn,easy,base

Author

Danny Rorabaugh, Apr 15 2015

Status

approved