%I #13 May 03 2019 07:46:44
%S 0,0,0,4,16,53,169,512,1706,6144,23040,87380,327680,1217097,4509419,
%T 16777216,62914560,237677216,902430720,3435973836,13102206738,
%U 50026607709,191312873561,733007751680,2814062572336,10823317585920,41694904974720,160842843834660
%N Number of 4-ary Lyndon words of length n over Z_4 with trace 1 and subtrace 1.
%C Same as the number of 4-ary Lyndon words of length n over Z_4 with trace 3 and subtrace 1.
%H Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI/GP scripts for miscellaneous math problems</a>
%H F. Ruskey, <a href="http://combos.org/TSlyndonZ4">4-ary Lyndon words with given trace and subtrace</a>
%Y Cf. A068596, A074403, A074404, A074405, A074406, A074408, A074409, A074410, A074411, A074412, A074413.
%K easy,nonn
%O 1,4
%A _Frank Ruskey_ and Nate Kube, Aug 22 2002
%E Terms a(16) onward from _Max Alekseyev_, Apr 09 2013