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 A074403 #15 Jul 22 2025 11:13:36 %S A074403 0,0,2,6,16,45,128,448,1706,6528,24576,90110,327680,1198665,4438966, %T A074403 16646144,62914560,238605640,905969664,3442684722,13102206738, %U A074403 49977848925,191126044672,732649837760,2814062572336,10825959997440,41705086880768,160862477970870 %N A074403 Number of 4-ary Lyndon words of length n over Z_4 with trace 0 and subtrace 1. %H A074403 Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI/GP scripts for miscellaneous math problems</a> %H A074403 F. Ruskey, <a href="http://combos.org/TSlyndonZ4">4-ary Lyndon words with given trace and subtrace</a> %Y A074403 Cf. A068596, A074404, A074405, A074406, A074407, A074408, A074409, A074410, A074411, A074412, A074413. %K A074403 easy,nonn %O A074403 1,3 %A A074403 _Frank Ruskey_ and Nate Kube, Aug 22 2002 %E A074403 Terms a(15) onward from _Max Alekseyev_, Apr 09 2013