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A032640
Numbers k such that k concatenated with itself is a lucky number.
3
3, 9, 21, 23, 51, 59, 63, 71, 75, 87, 89, 99, 105, 111, 117, 123, 129, 135, 143, 147, 153, 171, 173, 177, 191, 201, 237, 243, 255, 263, 285, 305, 309, 317, 327, 357, 363, 369, 371, 387, 389, 393, 431, 443, 459, 465, 467, 495, 497, 513, 521, 533, 561, 567, 573
OFFSET
1,1
LINKS
Kevin P. Thompson, Table of n, a(n) for n = 1..4215 (first 95 terms from Amiram Eldar)
EXAMPLE
123 is a member of the sequence since 123123 is a lucky number, i.e. A000959(10590) = 123123.
CROSSREFS
Sequence in context: A109612 A032668 A050839 * A245202 A127174 A251535
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
EXTENSIONS
More terms from Sascha Kurz, Mar 24 2002
STATUS
approved