%I #14 Jan 30 2015 04:24:03
%S 1,2,4,18,110,772,5936,48618,417398,3716972,34086194,320225348,
%T 3069943298,29943487732,296447910268,2973356043818,30166687749922,
%U 309197338572932,3198206243665998,33353864893990660,350443763627186256,3707087785160487888,39458245623693926384,422389058260155207568
%N Number of meanders of order n without 1-1 cuts.
%D S. K. Lando and A. K. Zvonkin, Plane and projective meanders, Séries Formelles et Combinatoire Algebrique. Laboratoire Bordelais de Recherche Informatique, Universite Bordeaux I, 1991, pp. 287-303.
%H I. Jensen, <a href="http://dx.doi.org/10.1088/0305-4470/33/34/301">A transfer matrix approach to the enumeration of plane meanders</a>, J. Phys. A 33, 5953-5963 (2000).
%H A. Panayotopoulos and P. Tsikouras, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL7/Panayotopoulos/panayo4.html">Meanders and Motzkin Words</a>, J. Integer Seqs., Vol. 7, 2004.
%H A. Panayotopoulos and P. Vlamos, <a href="http://dx.doi.org/10.1007/978-3-642-33412-2_49">Cutting Degree of Meanders</a>, Artificial Intelligence Applications and Innovations, IFIP Advances in Information and Communication Technology, Volume 382, 2012, pp 480-489; DOI 10.1007/978-3-642-33412-2_49. - From _N. J. A. Sloane_, Dec 29 2012
%F a(n) = A005315(n) - A192927(n).
%Y Cf. A005315, A192927.
%K nonn
%O 1,2
%A _Panayotis Vlamos_, Feb 25 2012