OFFSET
1,3
COMMENTS
After the digit 0 that starts the sequence, we have the 2nd digit of the sequence that is > 0, then the 3rd digit that is > the 2nd digit, then the 4th digit that is < the 3rd digit, the 5th digit that is < the 4th digit, etc. Considering the sequence from the digit-size point of view, we could see it as a kind of roller coaster going up two steps, than down two steps, than up a again two steps, etc.
LINKS
Jean-Marc Falcoz, Table of n, a(n) for n = 1..5004
EXAMPLE
The sequence starts with 0,1,2,10,3,4,20,5,6,21,7,8,30,... and indeed the digits form a kind of 2-step roller-coaster 0 < 1 < 2 > 1 > 0 < 3 < 4 > 2 > 0 < 5 < 6 > 2 > 1 < 7 < 8 > 3 > 0...
CROSSREFS
KEYWORD
AUTHOR
Eric Angelini and Jean-Marc Falcoz, Aug 02 2018
STATUS
approved