OFFSET
1,3
COMMENTS
The sequence is started with a(1) = 0 and always extended with the smallest integer not yet present and not leading to a contradiction.
LINKS
Jean-Marc Falcoz, Table of n, a(n) for n = 1..3003
EXAMPLE
The first 15 terms are:
0,1,10,100,2,110,20,3,21,11,120,4,200,5,30
Their successive digits are:
0,1,1,0,1,0,0,2,1,1,0,2,0,3,2,1,1,1,1,2,0,4,2,0,0,5,3,0
The even rank digits are here (between parentheses):
0,(1),1(0),1(0)0,(2),1(1)0,(2)0,(3),2(1),1(1),1(2)0,(4),2(0)0,(5),3(0),...
Erasing the digits in the parentheses:
0,( ),1( ),1( )0,( ),1( )0,( )0,( ),2( ),1( ),1( )0,( ),2( )0,( ),3( ),...
The surviving digits are:
0,1,1,0,1,0,0,2,1,1,0,2,0,3,...
Those are indeed the digits of the starting sequence.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini and Jean-Marc Falcoz, Mar 22 2017
STATUS
approved