cp's OEIS Frontend

A342164 A self-describing sequence: start with 0, then for each digit in each successive term, starting from the first term, append to the sequence its most recent position in the string formed by the concatenation of all previous terms.

%I A342164 #7 Mar 07 2021 14:47:40
%S A342164 0,1,2,3,4,5,6,7,8,9,10,11,12,15,17,19,16,23,18,27,30,27,22,27,24,39,
%T A342164 41,44,28,47,50,41,52,56,50,56,56,56,50,56,53,72,42,75,54,80,80,76,83,
%U A342164 80,85,92,90,80,54,99,94,99,86,99,98,99,108,99,108,99,108,99,126,99
%N A342164 A self-describing sequence: start with 0, then for each digit in each successive term, starting from the first term, append to the sequence its most recent position in the string formed by the concatenation of all previous terms.
%C A342164 After the leading zero taking the a(n)-th digit of the sequence returns the digits of the sequence.
%e A342164 The second term is 1 as the 0 in the first term appears as the first digit in the sequence. Likewise the third term is 2 as the 1 in the second term is the second digit of the sequence, and so on to the eleventh term.
%e A342164 As the eleventh term is 10 and has two digits, the twelfth and thirteenth terms give the most recent position of a 1 and 0 in the sequence, and they appear at the eleventh and twelfth position.
%e A342164 As the twelfth term is 11, the fourteenth and fifteenth terms give the most recent position of the two 1's. The last 1 appears at the fifteenth position, and after appending 15, which contains a 1, the most recent 1 now appears at the seventeenth position.
%Y A342164 Cf. A125132, A264646, A114308, A263563, A308387
%K A342164 nonn,base
%O A342164 0,3
%A A342164 _Scott R. Shannon_, Mar 03 2021