A137020 Numbers k such that k and k^2 use only the digits 1, 2, 8 and 9.

1, 9, 11, 91, 911

Offset

1,2

Comments

Generated with DrScheme.

No additional terms through 10^10. - Harvey P. Dale, Jul 04 2012

Links

Table of n, a(n) for n=1..5.

Jonathan Wellons, Tables of Shared Digits [archived]

Example

911^2 = 829921.

Mathematica

okQ[n_]:=Module[{u=Union[IntegerDigits[n^2]]}, And@@Table[MemberQ[ {1, 2, 8, 9}, u[[i]]], {i, Length[u]}]]; Flatten[Table[ Select[FromDigits/@ Tuples[{1, 2, 8, 9}, x], okQ], {x, 10}]] (* Harvey P. Dale, Jul 04 2012 *)

Crossrefs

Sequence in context: A289288 A137016 A053886 * A058304 A359457 A365221

Adjacent sequences: A137017 A137018 A137019 * A137021 A137022 A137023

Keyword

base,nonn,more

Author

Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008

Status

approved