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 A355911 #9 Sep 19 2022 07:07:34 %S A355911 1,1,2,2,2,4,4,4,4,6,8,8,8,8,8,12,12,14,16,16,16,16,16,16,24,24,24,26, %T A355911 28,28,32,32,32,32,32,32,32,40 %N A355911 Number of alt-unary-binary trees with n nodes. %H A355911 Don Knuth, <a href="http://cs.stanford.edu/~knuth/papers/ambidextrous.pdf">Ambidextrous Numbers</a>, Preprint, September 2022. See (13.4). %Y A355911 Cf. A355904-A355910, A355912, A355913. %K A355911 nonn,more %O A355911 1,3 %A A355911 _N. J. A. Sloane_, Sep 19 2022