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A137001
Numbers k such that k and k^2 use only the digits 1, 2, 4 and 9.
0
1, 2, 11, 12, 21, 212, 221911
OFFSET
1,2
COMMENTS
Generated with DrScheme.
LINKS
EXAMPLE
221911^2 = 49244491921.
CROSSREFS
Sequence in context: A136970 A136967 A213975 * A136996 A238109 A374596
KEYWORD
base,nonn,more
AUTHOR
Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
STATUS
approved