A006662 Number of meanders in which first bridge is 7. (Formerly M4921)

14, 14, 36, 57, 155, 316, 902, 2053, 6059, 14810, 44842, 115009, 355293, 943860, 2963536, 8086913, 25733325, 71725012, 230811370, 654472364, 2126296860, 6115504594, 20032488714, 58309793101

Offset

7,1

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=7..30.

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)

Crossrefs

Cf. A259974, A005316.

Sequence in context: A040183 A022348 A214463 * A247516 A135820 A165835

Adjacent sequences: A006659 A006660 A006661 * A006663 A006664 A006665

Keyword

nonn

Author

Simon Plouffe

Extensions

Offset corrected, terms a(19)-a(30) added, Andrew Howroyd, Dec 15 2015

Status

approved