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 A007499 M0598 #23 Jul 08 2025 17:05:06 %S A007499 2,3,4,12,20,55,127,371,1037,3249,10071,32913,108112,363618,1233938, %T A007499 4244102,14716095,51480027,181312939 %N A007499 Number of cases considered in a particular algorithm for enumerating hexaflexagrams. %C A007499 See O'Reilly reference for precise definition. %D A007499 Thomas J. O'Reilly, Classifying and Counting Hexaflexagrams, J. Rec. Math., 8 (1976), 182-187. %D A007499 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A007499 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a007/A007499.java">Java program</a> (github) %H A007499 Thomas J. O'Reilly, <a href="/A007499/a007499.pdf">Classifying and Counting Hexaflexagrams</a>, J. Rec. Math., 8 (1976), 182-187. [Annotated scanned copy] %Y A007499 Cf. A000207. %K A007499 nonn,more %O A007499 1,1 %A A007499 _N. J. A. Sloane_, _Robert G. Wilson v_, circa 1976 %E A007499 Title clarified and a(11)-a(19) from _Sean A. Irvine_, Jul 12 2022