%I A068923
%S A068923 1,4,4,2,3,3,3,5,5,6,8,8,11,13,14,19,21,25,32,35,44,53,60,76,88,104,
%T A068923 129,148,180,217,252,309,365,432,526,617,741,891,1049,1267,1508,1790,
%U A068923 2158,2557,3057,3666,4347,5215,6223,7404,8881,10570,12619,15104,17974
%N A068923 Number of ways to tile a 4 X n room with 1x2 Tatami mats. At most 3 Tatami 
               mats may meet at a point.
%F A068923 For n >= 9, a(n) = a(n-3) + a(n-5).
%F A068923 G.f.: x*(x+1)*(2*x^6+x^5+x^4-x^2-3*x-1)/(-1+x^5+x^3) [From Maksym Voznyy 
               (voznyy(AT)mail.ru), Jul 28 2009]
%Y A068923 Cf. A068929 for incongruent tilings, A068920 for more info.
%Y A068923 Sequence in context: A099655 A146899 A031351 this_sequence A103714 A112108 
               A021230
%Y A068923 Adjacent sequences: A068920 A068921 A068922 this_sequence A068924 A068925 
               A068926
%K A068923 easy,nonn
%O A068923 1,2
%A A068923 Dean Hickerson (dean.hickerson(AT)yahoo.com), Mar 11 2002
%E A068923 G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, 
               Sep 16 2009.