%I #8 Jul 10 2011 18:20:57
%S 0,4,20,120,696,4060,23660,137904,803760,4684660,27304196,159140520
%N Duplicate of A046729.
%H <a href="/index/Tu#2wis">Index entries for two-way infinite sequences</a>
%K dead
%O 0,2
