A136865 Numbers k such that k and k^2 use only the digits 0, 1, 4, 7 and 9.

0, 1, 7, 10, 70, 97, 100, 107, 700, 701, 970, 997, 1000, 1007, 1049, 1070, 1071, 7000, 7001, 7010, 7071, 9700, 9701, 9970, 9997, 10000, 10007, 10070, 10097, 10490, 10700, 10710, 14107, 70000, 70001, 70010, 70100, 70107, 70499, 70710, 97000, 97001, 97010, 99700, 99970, 99997, 100000, 100007, 100070, 100097, 100499, 100700, 100970, 104900, 107000

Offset

1,3

Comments

Generated with DrScheme.

Links

Jonathan Wellons, Table of n, a(n) for n = 1..1020

J. Wellons, Tables of Shared Digits [archived]

Example

4140170401071^2 = 17141010949904404997947041.

Mathematica

With[{c={0, 1, 4, 7, 9}}, Select[FromDigits/@Tuples[c, 6], SubsetQ[ c, IntegerDigits[ #^2]]&]] (* Harvey P. Dale, Aug 13 2020 *)

Crossrefs

Sequence in context: A187999 A097187 A115904 * A350533 A351685 A123797

Adjacent sequences: A136862 A136863 A136864 * A136866 A136867 A136868

Keyword

base,nonn,changed

Author

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

Status

approved