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A032698
Exactly 2 digits from {1,2,3,4,5,6,7,8,9} can precede a(n) to form a lucky number.
0
17, 45, 55, 57, 63, 69, 75, 81, 87, 99, 101, 105, 109, 117, 129, 131, 133, 135, 147, 153, 161, 167, 169, 171, 177, 181, 187, 189, 197, 201, 203, 207, 209, 213, 215, 217, 221, 227, 243, 245, 259, 261, 269, 271, 273, 279, 281, 289, 291, 293, 303, 309, 311
OFFSET
1,1
EXAMPLE
If a(n) = 303 then we find only '1'303 and '9'303 to be lucky numbers.
CROSSREFS
Cf. A000959.
Sequence in context: A227721 A140155 A221752 * A120099 A307293 A045570
KEYWORD
nonn,base,less
AUTHOR
Patrick De Geest, May 15 1998
STATUS
approved