A136915 Numbers k such that k and k^2 use only the digits 0, 2, 5 and 7.

0, 5, 50, 500, 505, 755, 5000, 5005, 5050, 7550, 50000, 50005, 50050, 50500, 50505, 75500, 500000, 500005, 500050, 500500, 500505, 500755, 505000, 505050, 755000, 5000000, 5000005, 5000050, 5000500, 5000505, 5000755, 5005000, 5005005, 5005050, 5007550, 5025505, 5050000, 5050005, 5050500, 7550000, 7550005, 50000000, 50000005, 50000050

Offset

1,2

Comments

Generated with DrScheme.

Links

Jonathan Wellons, Table of n, a(n) for n = 1..1077

J. Wellons, Tables of Shared Digits [archived]

Example

505050250050005^2 = 255075755075572575505000500025.

Mathematica

With[{c={0, 2, 5, 7}}, Select[FromDigits/@Tuples[c, 8], SubsetQ[c, IntegerDigits[#^2]]&]] (* Harvey P. Dale, Apr 27 2025 *)

Crossrefs

Sequence in context: A266028 A228751 A299868 * A136918 A136910 A267663

Adjacent sequences: A136912 A136913 A136914 * A136916 A136917 A136918

Keyword

base,nonn

Author

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

Status

approved