login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A046723 Number of semi-meanders of order n with 4 components. 2
1, 4, 17, 66, 254, 956, 3584, 13256, 49052, 179552, 658560, 2394504, 8724464, 31575096, 114451388, 412811544, 1490190544, 5360943684, 19288139802, 69245171564, 248463024330, 890477645192, 3188033497580, 11409453277272, 40771092374710, 145735210316376, 519955750491512 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

Andrew Howroyd, Table of n, a(n) for n = 4..40

P. Di Francesco, O. Golinelli and E. Guitter, Meander, folding and arch statistics, arXiv:hep-th/9506030, 1995.

CROSSREFS

Cf. A000682, A046726.

Sequence in context: A202555 A045992 A217539 * A291394 A244616 A030529

Adjacent sequences:  A046720 A046721 A046722 * A046724 A046725 A046726

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

a(15)-a(40) from Andrew Howroyd, Dec 07 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 16 23:45 EDT 2019. Contains 328103 sequences. (Running on oeis4.)