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List the positions of all digits 6 in the concatenation of all terms, not necessarily in order. This is the lexicographically earliest such sequence.
8

%I #17 Apr 18 2021 02:14:55

%S 2,6,4,60,61,9,62,13,63,16,19,64,23,65,26,29,66,30,35,67,39,68,43,69,

%T 46,49,600,54,601,59,666,6666,66660,73,602,78,603,83,604,88,605,93,

%U 606,95,101,607,106,110,608,116,609,115,125,610,131,611,136,140,612

%N List the positions of all digits 6 in the concatenation of all terms, not necessarily in order. This is the lexicographically earliest such sequence.

%C See A210415 for comments, links, and code.

%H Danny Rorabaugh, <a href="/A210420/b210420.txt">Table of n, a(n) for n = 1..1000</a>

%e The sequence cannot start with 1 because the first digit is not 6. Let us start with 2: the second digit is equal to 6. The third digit cannot be 3 because the third digit is not 6. So let it be 4. In the next position we now have 60 because it is the minimum number greater than 6 and starting with the digit 6. And so on.

%Y Cf. A210414, A210415, A210416, A210417, A210418, A210419, A210421, A210422, A210423.

%K nonn,base

%O 1,1

%A _Paolo P. Lava_, Mar 26 2012