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 A091970 #15 Aug 05 2018 11:40:04 %S A091970 0,0,1,0,0,1,1,1,1,2,0,0,1,0,0,1,1,1,1,2,1,0,0,1,0,0,1,1,1,1,2,0,0,1, %T A091970 0,0,1,1,1,1,2,1,1,1,1,2,1,1,1,1,2,1,1,1,1,2,2,1,0,0,1,0,0,1,1,1,1,2, %U A091970 0,0,1,0,0,1,1,1,1,2,1,0,0,1,0,0,1,1,1,1,2,0,0,1,0,0,1,1,1,1,2 %N A091970 a(1) = 0; for n>1, find largest integer k such that the word a(1)a(2)...a(n-1) is of the form xy^k for words x and y (where y has positive length), i.e., k = the maximal number of repeating blocks at the end of the sequence so far; then a(n) = floor(k/2). %C A091970 When does the first 3 occur? The first 4? %H A091970 F. J. van de Bult, D. C. Gijswijt, J. P. Linderman, N. J. A. Sloane and Allan Wilks, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL10/Sloane/sloane55.html">A Slow-Growing Sequence Defined by an Unusual Recurrence</a>, J. Integer Sequences, Vol. 10 (2007), #07.1.2. %H A091970 F. J. van de Bult, D. C. Gijswijt, J. P. Linderman, N. J. A. Sloane and Allan Wilks, A Slow-Growing Sequence Defined by an Unusual Recurrence [<a href="http://neilsloane.com/doc/gijs.pdf">pdf</a>, <a href="http://neilsloane.com/doc/gijs.ps">ps</a>]. %H A091970 <a href="/index/Ge#Gijswijt">Index entries for sequences related to Gijswijt's sequence</a> %Y A091970 A (presumably) even slower-growing sequence than A090822. %K A091970 nonn %O A091970 1,10 %A A091970 _N. J. A. Sloane_, Mar 14 2004