%I A103999
%S A103999 1,1,1,1,6,1,1,16,34,1,1,54,196,198,1,1,196,1666,2704,1154,1,1,726,
%T A103999 16384,64152,37636,6726,1,1,2704,171394,1844164,2549186,524176,39202,1,
%U A103999 1,10086,1844164,57523158,220581904,101757654,7300804,228486,1,1
%N A103999 Square array T(M,N) read by antidiagonals: number of dimer tilings of 
               a 2M x 2N Klein bottle.
%H A103999 Author?, <a href="http://www.kleinbottle.com">About Klein bottles</a>
%H A103999 W. T. Lu and F. Y. Fu, <a href="http://arXiv.org/abs/cond-mat/9906154">
               Dimer statistics on the Moebius strip and the Klein bottle</a>
%F A103999 T(M, N) = Prod[m=1..M, Prod[n=1..N, 4sin(Pi*(4n-1)/(4N))^2 + 4sin(Pi*(2m-1)/
               (2M))^2 ]].
%e A103999 1,1,1,1,1,1,1,
%e A103999 1,6,34,198,1154,6726,39202,
%e A103999 1,16,196,2704,37636,524176,7300804,
%e A103999 1,54,1666,64152,2549186,101757654,4064620168,
%e A103999 1,196,16384,1844164,220581904,26743369156,3252222705664,
%e A103999 1,726,171394,57523158,21050622914,7902001927776,2988827208115522,
%Y A103999 Rows include A003499, A067902+2. Columns include A003500+2.
%Y A103999 Cf. A099390, A103997.
%Y A103999 Sequence in context: A109001 A152602 A119726 this_sequence A154985 A157275 
               A157268
%Y A103999 Adjacent sequences: A103996 A103997 A103998 this_sequence A104000 A104001 
               A104002
%K A103999 nonn,tabl
%O A103999 0,5
%A A103999 Ralf Stephan, Feb 26 2005