cp's OEIS Frontend

A366549 a(0) = 0; for n > 0, a(n) is the number of terms prior to and including the term a(n-1-a(n-1)) that equal a(n-1-a(n-1)).

%I A366549 #13 Oct 15 2023 09:26:17
%S A366549 0,1,1,1,2,2,3,3,1,2,2,4,2,4,3,1,3,2,5,2,6,3,1,5,1,2,2,7,1,1,8,6,8,7,
%T A366549 9,8,1,3,1,6,2,11,1,1,12,2,13,2,11,6,13,6,11,1,3,5,2,7,2,13,1,3,14,2,
%U A366549 8,13,3,15,3,4,4,9,1,2,2,16,3,16,8,4,1,5,11,2,4,17,10,11,11,2,5,1,5
%N A366549 a(0) = 0; for n > 0, a(n) is the number of terms prior to and including the term a(n-1-a(n-1)) that equal a(n-1-a(n-1)).
%C A366549 In the first 10 million terms the value 1 appears the most often, 13584 times, although the count of neighboring values is less than 2% different. It is unknown if this stays the most common term as n increases. In the same range on fifty occasions there are three consecutive equal terms, the second time, after the three 1's at the start of the sequence, being a(406) = a(407) = a(408) = 11. It is unknown if four or more consecutive terms eventually appear.
%H A366549 Scott R. Shannon, <a href="/A366549/b366549.txt">Table of n, a(n) for n = 0..10000</a>
%H A366549 Scott R. Shannon, <a href="/A366549/a366549.png">Image of the first 10 million terms</a>.
%e A366549 a(2) = 1 as a(2-1-a(2-1)) = a(1-1) = a(0) = 0, and there is one term prior to or equal to a(0) that equals 0, namely a(0).
%e A366549 a(6) = 3 as a(6-1-a(6-1)) = a(5-2) = a(3) = 1, and there are three terms prior to or equal to a(3) that equal 1, namely a(1), a(2) and a(3).
%Y A366549 Cf. A366548, A363193, A354971, A181391, A342585.
%K A366549 nonn,look
%O A366549 0,5
%A A366549 _Scott R. Shannon_, Oct 13 2023