%I #9 Dec 26 2019 05:44:42
%S 1,1,2,2,3,2,2,3,3,4,4,2,4,3,3,5,3,3,4,4,5,4,4,2,5,6,2,5,6,3,6,4,3,6,
%T 6,5,4,4,3,4,5,5,6,7,5,4,4,6,4,4,7,5,5,6,5,6,7,8,4,5,7,7,6,7,8,6,3,6,
%U 7,8,5,5,8,3,6,9,5,8,7,5,9,7,7,8,6,5,8
%N Lexicographically earliest sequence of positive terms such that for any n > 0 and k > 0, a(n+2*k) <> gcd(a(n), a(n+k)).
%C This sequence differs radically from the variant where we consider nonnegative terms (A330622).
%H Rémy Sigrist, <a href="/A330623/b330623.txt">Table of n, a(n) for n = 1..10000</a>
%H Rémy Sigrist, <a href="/A330623/a330623.png">Scatterplot of the first 250000 terms</a>
%H Rémy Sigrist, <a href="/A330623/a330623.txt">C program for A330623</a>
%o (C) See Links section.
%Y Cf. A330622 (nonnegative variant).
%Y See A330267 for similar sequences.
%K nonn
%O 1,3
%A _Rémy Sigrist_, Dec 21 2019
