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A137018
Numbers k such that k and k^2 use only the digits 1, 2, 7, 8 and 9.
1
1, 9, 11, 17, 27, 89, 91, 911, 989, 2777, 2827, 2877, 9911, 27877, 28127, 88189, 88277, 88877, 98989, 99891, 172891, 279127, 282827, 287891, 988877, 2879189, 9989891, 9998891, 29711811, 87919777, 88978189, 99899891, 112818127, 277817777, 277871911, 277987917, 278781777, 279781911, 287919777, 888812811, 1727112877, 2778718989
OFFSET
1,2
COMMENTS
Generated with DrScheme.
LINKS
J. Wellons, Tables of Shared Digits [archived]
EXAMPLE
278787181898989^2 = 77722292791179979928199222121.
CROSSREFS
Sequence in context: A111391 A077788 A339048 * A182391 A346465 A263722
KEYWORD
base,nonn
AUTHOR
Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
STATUS
approved