%I M0374 #30 Jun 28 2017 15:17:37
%S 1,1,2,2,8,12,52,86,400,710,3404,6316,30888,59204,293192,576018,
%T 2877184,5764430,28967428,58970568,297634344,614037754,3109111064
%N Number of projective meanders.
%D S. K. Lando and A. K. Zvonkin, "Plane and projective meanders", Séries Formelles et Combinatoire Algébrique. Laboratoire Bordelais de Recherche Informatique, Université Bordeaux I, 1991, pp. 287-303.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H S. K. Lando and A. K. Zvonkin , <a href="/A005316/a005316_1.pdf">Plane and projective meanders</a>, Séries Formelles et Combinatoire Algébrique. Laboratoire Bordelais de Recherche Informatique, Université Bordeaux I, 1991, pp. 287-303. (Annotated scanned copy)
%H S. K. Lando and A. K. Zvonkin, <a href="http://dx.doi.org/10.1016/0304-3975(93)90316-L">Plane and projective meanders</a>, Theoretical Computer Science Vol. 117 (1993), no. 1-2, 227-241.
%K nonn,nice,more
%O 0,3
%A _N. J. A. Sloane_, _Simon Plouffe_
%E a(16)-a(22) from _Andrew Howroyd_, Mar 30 2017