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.
%I A131389 #15 Aug 08 2025 03:48:01 %S A131389 0,1,2,-1,3,4,-2,-3,6,-4,5,7,-5,8,-6,-7,9,10,-8,11,-10,12,-9,-11,13, %T A131389 14,-13,-12,15,16,-14,-15,17,18,-16,19,-17,20,-19,21,-18,22,-20,-21, %U A131389 24,-22,23,25,-23,26,-25,27,-24,28,-26,-27,30,29,-31,32,-28,31,-29,33,-30,34,-32,-33,35,36,-34 %N A131389 Sequence (d(n)) generated by Rule 1 (see Comments) with a(1) = 1 and d(1) = 0. %C A131389 Rule 1 is given at A131388. Conjecture: Every integer occurs exactly once in A131389. %H A131389 Clark Kimberling, <a href="/A131389/b131389.txt">Table of n, a(n) for n = 1..1000</a> %F A131389 This is the sequence d( ) in the formula for A131388. %e A131389 See A131388. %t A131389 (* See A131388. *) %Y A131389 Cf. A131388, A131390, A131391, A131392, A131393, A131394, A131395, A131396, A131397. %K A131389 sign %O A131389 1,3 %A A131389 _Clark Kimberling_, Jul 05 2007 %E A131389 Definition clarified by _Clark Kimberling_, May 12 2015