[math-fun] Yellows = non-Yellows

Hello Math-Fun, S is the lexicographically earliest seq of distinct integers [separated only by a comma, and starting with a(1) = 1] such that the yellow digits appear in the exact same order as the non yellow digits. A yellow digit is a digit in contact with at least one comma of S. Question: For which a(n) will the quantity of yellow digits equal the quantity of non yellow digits [if such an a(n) exists]? S starts like this, if I am not wrong: S = 1,2,3,4,5,6,78,9,10,11,12,13,...,97,98,99, 110,120,130,140,150,160,170,180,190,111, 100,112,113,114,121,115,131,116,141,117,... (S is perhaps already in the OEIS -- but I could not find it; anyway the question remains). Best, É. à+ É. Catapulté de mon aPhone