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 A074413 #16 Jul 22 2025 11:14:32
%S A074413 0,0,2,6,16,44,128,440,1706,6496,24576,90004,327680,1198336,4438966,
%T A074413 16645120,62914560,238602228,905969664,3442672434,13102206738,
%U A074413 49977802752,191126044672,732649663000,2814062572336,10825959342080,41705086880768,160862475536676
%N A074413 Number of 4-ary Lyndon words of length n over Z_4 with trace 2 and subtrace 3.
%H A074413 Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI/GP scripts for miscellaneous math problems</a>
%H A074413 F. Ruskey, <a href="http://combos.org/TSlyndonZ4">4-ary Lyndon words with given trace and subtrace</a>
%e A074413 a(4;2,3)=6 since the six 4-ary Lyndon words of trace 2, subtrace 3 and length 4 are { 0123, 0132, 0213, 0231, 0312, 0321 }.
%Y A074413 Cf. A068596, A074403, A074404, A074405, A074406, A074407, A074408, A074409, A074410, A074411, A074412.
%K A074413 easy,nonn
%O A074413 1,3
%A A074413 _Frank Ruskey_ and Nate Kube, Aug 22 2002
%E A074413 Terms a(15) onward from _Max Alekseyev_, Apr 09 2013