OFFSET
1,2
COMMENTS
This is the lexicographically first such sequence starting with a(1)=1 and being always extended with the smallest integer not yet present that doesn't lead to a contradiction.
LINKS
Eric Angelini, Table of n, a(n) for n = 1..1002
EXAMPLE
The blocks of odd digits are indicated here by parentheses; the successive block-sizes are 1, 2, 3, 5, 4, 6, 7,... which reproduces the sequence itself:
(1),2,(3,5),4,6,(7,9,1)0,8,(11,13,1)2,(15,17),20,(19,31,33),2(1,35,37,39),22,...
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Jean-Marc Falcoz, Jul 25 2016
STATUS
approved