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 A294848 #15 Jul 26 2018 07:05:23 %S A294848 1,2,3,4,6,7,10,11,14,16,19,20,24,25,28,32,37,38,43,44,49,53,56,57,63, %T A294848 66,69,73,80,81 %N A294848 a(n) is the total number of horizontal line segments in the diagram of the symmetries of sigma described in A236104 after n-th stage, with a(0) = 1. %C A294848 Since the diagram is symmetrics a(n) is also the number of vertical line segments after n-th stage. For a diagram see A294847. %F A294848 a(n) = A294847(n)/2. %Y A294848 Cf. A196020, A235791, A236104, A236106, A237591, A237593, A245092, A293750, A294847, A294849. %K A294848 nonn,more %O A294848 0,2 %A A294848 _Omar E. Pol_, Nov 09 2017