A137106 Numbers k such that k and k^2 use only the digits 2, 4, 7 and 8.

2, 22, 28, 88, 278, 472, 478, 2878

Offset

1,1

Comments

Generated with DrScheme.

No further terms up to 20 billion. - Harvey P. Dale, Dec 15 2011

Links

Table of n, a(n) for n=1..8.

Jonathan Wellons, Tables of Shared Digits [archived]

Example

2878^2 = 8282884.

Mathematica

oksQ[n_]:=Module[{idn2=Union[IntegerDigits[n^2]]}, And@@Table[MemberQ[{2, 4, 7, 8}, idn2[[i]]], {i, Length[idn2]}]]; Select[FromDigits/@Flatten[ Table[ Tuples[ {2, 4, 7, 8}, n], {n, 9}], 1], oksQ] (* Harvey P. Dale, Dec 15 2011 *)

Crossrefs

Sequence in context: A074160 A368406 A137074 * A053962 A111771 A052001

Adjacent sequences: A137103 A137104 A137105 * A137107 A137108 A137109

Keyword

base,nonn,more,changed

Author

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

Status

approved