A006663 Number of projective meanders. (Formerly M0374)

1, 1, 2, 2, 8, 12, 52, 86, 400, 710, 3404, 6316, 30888, 59204, 293192, 576018, 2877184, 5764430, 28967428, 58970568, 297634344, 614037754, 3109111064

Offset

0,3

References

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.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=0..22.

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. (Annotated scanned copy)

S. K. Lando and A. K. Zvonkin, Plane and projective meanders, Theoretical Computer Science Vol. 117 (1993), no. 1-2, 227-241.

Crossrefs

Sequence in context: A087955 A026537 A089248 * A094941 A002785 A301603

Adjacent sequences: A006660 A006661 A006662 * A006664 A006665 A006666

Keyword

nonn,nice,more

Author

N. J. A. Sloane, Simon Plouffe

Extensions

a(16)-a(22) from Andrew Howroyd, Mar 30 2017

Status

approved