OFFSET
1,3
COMMENTS
This is the lexicographically first such sequence, starting with a(1)=0, that was 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 "5" of the sequence [0,1,2,3,4,5,50]; then there is 1 digit between the next pair of "5": [50,51]; then there are 2 digits between the next pair of "5": [51,6,52]; then there are 3 digits between the next pair of "5": [52,7,8,53]; then there are 4 digits between the next pair of "5": [53,9,10,54]; then there are 5 digits between the next pair of "5": [54,11,12,56]; then there are 50 digits between the next pair of "5": [56,13,14,16,17,18,19,20,21,22,23,24,26,27,28,29,30,31,32,33,34,36,37,38,39,15], etc. The quantities 0, 1, 2, 3, 4, 5, 50,... rebuild the starting sequence.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini and Lars Blomberg, May 23 2016
STATUS
approved