A137040 Numbers k such that k and k^2 use only the digits 1, 3, 6 and 8.

1, 6, 8131, 116881, 1366881

Offset

1,2

Comments

Generated with DrScheme.

Likely finite. a(6) > 10^30 if it exists. - Max Alekseyev, Jan 15 2025

Links

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

Jonathan Wellons, Tables of Shared Digits [archived]

Example

1366881^2 = 1868363668161.

Mathematica

With[{c={1, 3, 6, 8}}, Select[Flatten[Table[FromDigits/@Tuples[c, n], {n, 7}]], SubsetQ[c, IntegerDigits[#^2]]&]] (* Harvey P. Dale, Jul 07 2025 *)

Crossrefs

Sequence in context: A188979 A158880 A341874 * A357805 A172733 A361901

Adjacent sequences: A137037 A137038 A137039 * A137041 A137042 A137043

Keyword

base,nonn,more

Author

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

Status

approved