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 A195211 #38 Oct 20 2017 12:10:07 %S A195211 1,5,51,502,4995,49999,499980,4999995,50000202,499999731,5000005565, %T A195211 50000013114,499999997503,4999999971938,49999999974390, %U A195211 499999999976909,4999999999414101,50000000022964476,500000000029433861,4999999999986496894 %N A195211 Number of 2s in the first 10^n entries of the generalized Kolakoski-(2,3) sequence A071820. %H A195211 J. Nilsson, <a href="http://arxiv.org/abs/1110.4228">A Space Efficient Algorithm for the Calculation of the Digit Distribution in the Kolakoski Sequence</a>, arXiv preprint arXiv:1110.4228 [math.CO], 2011, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL15/Nilsson/nilsson5.html">J. Int. Seq. 15 (2012) #12.6.7</a> %e A195211 The first entries of the Kolakoski-(2,3) sequence, A071820, are 2233222333... From this we see that a(0)=1, since the first letter is 2, and a(1) = 5 since among the first 10 letters 5 of them are 2s. %o A195211 (C) /* See A195206. - _Ed Wynn_, Jun 24 2014 */ %Y A195211 Cf. A000002, A071820. %K A195211 nonn %O A195211 0,2 %A A195211 _Johan Nilsson_, Sep 13 2011 %E A195211 a(13)-a(14) from _Ed Wynn_, Jun 24 2014 %E A195211 a(15)-a(19) from _Hiroaki Yamanouchi_, Jul 25 2017