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 A071962 #18 Dec 14 2021 12:08:26 %S A071962 1,2,4,10,26,70,216,682,2264,7960,29262,113256,452586,1886306,8109828, %T A071962 36274448,167157176 %N A071962 Number of double points of the map that, for each term t of a sequence, counts the preceding terms that are greater than or equal to t. %C A071962 It would be nice to have a formula or recurrence! %H A071962 Zoran Sunic, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL5/Sunik/sunik3.html">Young tableaux and other mutually describing sequences</a>, Journal of Integer Sequences, Vol. 5 (2002), Article 02.1.5 %H A071962 Zoran Sunic, <a href="https://doi.org/10.37236/1745">Self-Describing Sequences and the Catalan Family Tree</a>, Electronic Journal of Combinatorics, 10 (2003) #N5. %e A071962 The ten double points for n=3 form the following 5 pairs: (0000,0123), (0003,0120), (0020,0103), (0023,0100), (0021,0101) %K A071962 nonn,more %O A071962 0,2 %A A071962 _Zoran Sunic_, Jun 24 2002 %E A071962 More terms from _John W. Layman_, Jul 01 2002