OFFSET
1,3
COMMENTS
This is the lexicographically first such sequence, starting with a(1)=0; it is always extended with the smallest integer not already present in the sequence and not leading to a contradiction.
EXAMPLE
There are 0 digits between the first two "8" of the sequence [0,1,2,3,4,5,6,7,8,80]; then there is 1 digit between the next pair of "8": [80,81]; then there are 2 digits between the next pair of "8": [81,9,82]; then there are 3 digits between the next pair of "8": [82,10,83]; then there are 4 digits between the next pair of "8": [83,11,18]; then there are 5 digits between the next pair of "8": [18,12,13,28], etc. The quantities 0, 1, 2, 3, 4, 5,... rebuild the starting sequence. The next "gaps" will thus contain 6 digits, then 7, then 8, then 80...
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini and Lars Blomberg, May 23 2016
STATUS
approved