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 A074409 #15 Jul 22 2025 11:14:09
%S A074409 0,0,1,4,16,53,160,512,1706,6144,23133,87380,327680,1217097,4508328,
%T A074409 16777216,62914560,237677216,902444517,3435973836,13102206738,
%U A074409 50026607709,191312691200,733007751680,2814062572336,10823317585920,41694907460224,160842843834660
%N A074409 Number of 4-ary Lyndon words of length n over Z_4 with trace 1 and subtrace 3.
%C A074409 Same as the number of 4-ary Lyndon words of length n over Z_4 with trace 3 and subtrace 3.
%H A074409 Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI/GP scripts for miscellaneous math problems</a>
%H A074409 F. Ruskey, <a href="http://combos.org/TSlyndonZ4">4-ary Lyndon words with given trace and subtrace</a>
%e A074409 a(4;3,3)=4 since the four 4-ary Lyndon words of trace 3, subtrace 3 and length 4 are { 0111, 0133, 0313, 0331 }.
%Y A074409 Cf. A068596, A074403, A074404, A074405, A074406, A074407, A074408, A074410, A074411, A074412, A074413.
%K A074409 easy,nonn
%O A074409 1,4
%A A074409 _Frank Ruskey_ and Nate Kube, Aug 22 2002
%E A074409 Terms a(15) onward from _Max Alekseyev_, Apr 09 2013