A136955 Numbers k such that k and k^2 use only the digits 0, 4, 6, 7 and 9.

0, 7, 64, 70, 97, 640, 700, 970, 997, 6400, 6907, 7000, 7064, 9700, 9970, 9997, 64000, 69070, 70000, 70640, 77974, 97000, 99700, 99747, 99970, 99997, 640000, 666907, 667907, 690700, 700000, 700497, 706400, 774647, 777676, 779740, 970000, 997000, 997470, 999700, 999747, 999970, 999997, 6400000, 6400774, 6669070, 6679070, 6907000, 7000000

Offset

1,2

Comments

Generated with DrScheme.

Links

Jonathan Wellons, Table of n, a(n) for n = 1..714

J. Wellons, Tables of Shared Digits [archived]

Example

700709640764747^2 = 490994000660660790706997974009.

Mathematica

With[{c={0, 4, 6, 7, 9}}, Select[FromDigits/@Tuples[c, 7], SubsetQ[ c, IntegerDigits[ #^2]]&]] (* Harvey P. Dale, Oct 11 2020 *)

Crossrefs

Sequence in context: A036287 A116231 A195630 * A027767 A055537 A333991

Adjacent sequences: A136952 A136953 A136954 * A136956 A136957 A136958

Keyword

base,nonn

Author

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

Status

approved