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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A350226 a(n) is the length of the longest sequence of distinct numbers in arithmetic progression in the interval 0..n, ending with n and where the Thue-Morse sequence (A010060) is constant.

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%I A350226 #15 Jan 22 2023 16:03:15
%S A350226 1,1,2,2,2,2,3,3,2,4,3,2,5,3,3,6,2,3,7,4,5,3,4,3,5,5,4,4,6,3,6,7,2,4,
%T A350226 3,5,7,7,4,6,5,5,6,3,5,6,3,6,5,7,7,5,5,4,7,4,8,6,4,4,6,6,7,8,2,3,8,5,
%U A350226 6,3,5,5,9,7,7,7,6,4,6,7,5,5,8,5,6,6,4
%N A350226 a(n) is the length of the longest sequence of distinct numbers in arithmetic progression in the interval 0..n, ending with n and where the Thue-Morse sequence (A010060) is constant.
%C A350226 In other words, a(n) is the greatest k > 0 such that A010060(n) = A010060(n - i*d) for i = 0..k-1 and some d > 0 (see A350285 for the least such d).
%C A350226 This sequence is unbounded (this is a consequence of Van der Waerden's theorem).
%H A350226 Rémy Sigrist, <a href="/A350226/b350226.txt">Table of n, a(n) for n = 0..8191</a>
%H A350226 Rémy Sigrist, <a href="/A350226/a350226.txt">C program for A350226</a>
%e A350226 For n = 12:
%e A350226 - the first 13 terms of A010060 are:
%e A350226          0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0
%e A350226          ^        ^        ^        ^        ^
%e A350226 - A010060(0) = A010060(3) = A010060(6) = A010060(9) = A010060(12),
%e A350226 - and there is no longer sequence of distinct numbers <= 12 in arithmetic progression ending in 12 with this property,
%e A350226 - so a(12) = 5.
%o A350226 (C) See Links section.
%Y A350226 Cf. A005346, A010060, A342818, A342827, A350235 (records), A350285 (least first differences).
%K A350226 nonn
%O A350226 0,3
%A A350226 _Rémy Sigrist_, Dec 20 2021