[seqfan] Digit "k" is visible in a(a(n)) of S(k).

[Eric Angelini]

Hello SeqFans,
The digit "k" is visible in a(a(n)) of S(k).

For k=0:
S(0)=2,10,4,20,6,30,8,40,11,50,60,13,70,15,80,17,90,19,100,101,22,102,24,103,26,104,28,105,31,106,107,33,108,35,109,37,110,39,...

For k=1:
S(1)=1,3,10,5,11,7,12,9,13,14,15,16,17,18,19,21,31,41,51,22,61,71,24,81,26,91,28,100,30,101,102,33,104,35,105,37,106,39,...

Etc.
S(k) never shows twice the same integer and is always the lexicographically first sequence with the property.

Best,
É.