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A303462
Lexicographically earliest sequence of distinct terms such that the digits succession stays the same if every second digit among all sequence terms is erased.
1
1, 2, 20, 200, 3, 210, 10, 4, 30, 21, 100, 5, 110, 6, 40, 300, 7, 22, 11, 120, 50, 8, 51, 12, 130, 9, 60, 400, 13, 70, 80, 17, 32, 42, 31, 41, 61, 52, 90, 15, 101, 81, 53, 14, 16, 23, 18, 310, 19, 26, 102, 410, 103, 113, 27, 104, 800, 71, 37, 33, 62, 24, 72, 43, 91, 34, 111, 63, 105, 82, 29
OFFSET
1,2
COMMENTS
The sequence starts with a(1) = 1 and is always extended with the smallest integer not used so far that doesn't lead to a contradiction. It is conjectured that this sequence is a permutation of the integers > 0.
LINKS
EXAMPLE
The sequence starts with:
1,2,20,200,3,210,10,4,30,21,100,5,110,6,40,300,7,22,11,120
If 1 out of 2 digit is erased, we get:
1,.,2.,2.0,.,2.0,.0,.,3.,2.,1.0,.,1.0,.,4.,3.0,.,2.,1.,1.0
This succession of digits is the same as the starting sequence.
CROSSREFS
Sequence in context: A001078 A299865 A001253 * A085586 A322298 A136902
KEYWORD
nonn,base
AUTHOR
Eric Angelini and Lars Blomberg, Apr 24 2018
STATUS
approved