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A032650
Lucky numbers that are concatenations of a number k with itself.
3
33, 99, 2121, 2323, 5151, 5959, 6363, 7171, 7575, 8787, 8989, 9999, 105105, 111111, 117117, 123123, 129129, 135135, 143143, 147147, 153153, 171171, 173173, 177177, 191191, 201201, 237237, 243243, 255255, 263263, 285285, 305305, 309309, 317317
OFFSET
1,1
LINKS
Kevin P. Thompson, Table of n, a(n) for n = 1..4215 (first 95 terms from Amiram Eldar)
FORMULA
a(n) = A032640(n) || A032640(n), where || denotes concatenation. - Kevin P. Thompson, Nov 09 2021
CROSSREFS
Intersection of A000959 and A020338.
Cf. A032640.
Sequence in context: A044601 A195315 A098441 * A284986 A133901 A008880
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
EXTENSIONS
More terms from Sascha Kurz, Mar 24 2002
Edited by Charles R Greathouse IV, Apr 26 2010
STATUS
approved