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 "6" of the sequence [0,1,2,3,4,5,6,60]; then there is 1 digit between the next pair of "6": [60,61]; then there are 2 digits between the next pair of "6": [61,7,62]; then there are 3 digits between the next pair of "6": [62,8,9,63]; then there are 4 digits between the next pair of "6": [63,10,16]; then there are 5 digits between the next pair of "6": [16,11,12,26]; then there are 6 digits between the next pair of "6": [26,13,14,15,64]; then there are 60 digits between the next pair of "6": [64,17,18,19,20,21,22,23,24,25,27,28,29,30,31,32,33,34,35,37,38,39,40,41,42,43,44,45,47,48,36], etc. The quantities 0, 1, 2, 3, 4, 5, 6, 60,... rebuild the starting sequence.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini and Lars Blomberg, May 23 2016
STATUS
approved