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A276104
Lexicographically first sequence (with no duplicate term) where all the digits "1" are separated by two digits.
0
1, 2, 3, 10, 4, 12, 5, 13, 6, 14, 7, 15, 8, 16, 9, 17, 21, 20, 18, 31, 22, 19, 31, 23, 100, 102, 103, 104, 105, 106, 107, 108, 109, 120, 122, 123, 124, 125, 126, 127, 128, 129, 130, 132, 133, 134, 135, 136, 137, 138, 139, 140, 142, 143, 144, 145, 146, 147, 148, 149, 150
OFFSET
1,2
COMMENTS
The sequence is started with a(1)=1 and always extended with the smallest integer not yet used that does not lead to a contradiction.
EXAMPLE
To match the infinite digit-pattern 1..1..1..1..1..1.. (etc.) one must use the integer 10 after the third term (which is 3), then use the integer 4, then use the integer 12 (as 11 is forbidden: no integer with consecutive 1's is allowed), etc.
CROSSREFS
Sequence in context: A307591 A031275 A306465 * A376370 A329804 A274299
KEYWORD
nonn,base
AUTHOR
Eric Angelini, Aug 18 2016
STATUS
approved