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A137009 Numbers k such that k and k^2 use only the digits 1, 2, 5, 7 and 9. 1
1, 5, 11, 15, 27, 77, 227, 527, 715, 1515, 1711, 2777, 7227, 7715, 22715, 52915, 71911, 97527, 159911, 275527, 277977, 715511, 727511, 977511, 2791515, 7219777, 7557511, 7715515, 7727711, 7727715, 9591515, 9777515, 9797511, 9797715, 9955511, 11292915, 12292915, 17255515, 27771527, 27797715, 27797977, 27915515, 71971911, 72299211 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Generated with DrScheme.

LINKS

Jonathan Wellons, Table of n, a(n) for n = 1..272

J. Wellons, Tables of Shared Digits

EXAMPLE

759722171291527^2 = 577177777551912291775221991729.

MATHEMATICA

With[{c={1, 2, 5, 7, 9}}, Select[Flatten[Table[FromDigits/@Tuples[c, n], {n, 8}]], SubsetQ[ c, IntegerDigits[#^2]]&]] (* Harvey P. Dale, Oct 14 2020 *)

CROSSREFS

Sequence in context: A314077 A314078 A314079 * A340131 A290199 A034905

Adjacent sequences:  A137006 A137007 A137008 * A137010 A137011 A137012

KEYWORD

base,nonn

AUTHOR

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

STATUS

approved

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Last modified October 26 00:52 EDT 2021. Contains 348256 sequences. (Running on oeis4.)