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 A318241 #20 Oct 09 2019 20:57:10 %S A318241 0,1,1,3,3,4,4,4,4,6,6,6,7,7,7,9,9,9,10,10,10,12,12,12,13,13,13 %N A318241 Column 3 of array in A318240. %C A318241 The next value a(28) is either 15 or 16. %C A318241 a(6k+1) = a(6k+2) = a(6k+3) = 3k+1 for k >= 1. This follows from the solution to Kirkman's schoolgirl problem with n schoolgirls. %C A318241 The values of a(6k), a(6k-1) and a(6k-2) are either 3k or 3k+1. %H A318241 D. K. Ray-Chaudhuri and Richard M. Wilson, <a href="https://doi.org/10.1090/pspum/019">Solution of Kirkman's schoolgirl problem</a>, in Proceedings of Symposia in Pure Mathematics, Volume 19, 1971. %H A318241 Wikipedia, <a href="https://en.wikipedia.org/wiki/Kirkman%27s_schoolgirl_problem">Kirkman's schoolgirl problem</a> %Y A318241 Cf. A318240. %K A318241 nonn,more %O A318241 1,4 %A A318241 _Floris P. van Doorn_, Aug 25 2018