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 A248805 #9 Nov 22 2017 01:15:04 %S A248805 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, %T A248805 0,0,0,0,0,0,0,0,0,0,0,0,1,-1,0,0,0,0,0,0,0,1,-1,0,0,0,0,0,0,0,0,0,0, %U A248805 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 %N A248805 The difference A156257(n)-A074292(n). %C A248805 Related to the position and frequency of runs of length 2 in the Kolakoski sequence A000002. %C A248805 Possible values are -1, 0, 1, and a 1 seems to be always followed soon by a -1, indicating that the two sequences A074292 and A156257 are not equal but rather close (this might help to show the equality of the proportions of 1 and 2 in the Kolakoski sequence). %H A248805 Jean-Christophe Hervé, <a href="/A248805/b248805.txt">Table of n, a(n) for n = 1..5000</a> %p A248805 A248805 := proc(n) %p A248805 A156257(n)-A074292(n) ; %p A248805 end proc: %p A248805 seq(A248805(n),n=1..80) ; # _R. J. Mathar_, Nov 15 2014 %Y A248805 Cf. A000002, A074292, A156257. %K A248805 sign %O A248805 1,1 %A A248805 _Jean-Christophe Hervé_, Oct 11 2014