login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A284416 Number of self-avoiding planar walks of length 2n starting at (0,0), ending at (n,0), remaining in the first quadrant and using steps (0,1), (1,0), (1,1), (-1,1), and (1,-1) with the restriction that (0,1) is never used below the diagonal and (1,0) is never used above the diagonal. 3
1, 1, 1, 7, 17, 116, 536, 3732, 21609, 152225, 991680, 7142207, 49671146, 364955208, 2644449147, 19764753353, 147264417970, 1116423286310, 8488332597668, 65109780090520, 502742629038600, 3893865922507871, 30436537169536769, 237651376621912220 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..360

Alois P. Heinz, Animation of a(5)=116 walks

Wikipedia, Lattice path

Wikipedia, Self-avoiding walk

FORMULA

a(n) = A284414(n,2n).

CROSSREFS

Cf. A284414.

Sequence in context: A067185 A205989 A262474 * A063384 A165246 A266382

Adjacent sequences:  A284413 A284414 A284415 * A284417 A284418 A284419

KEYWORD

nonn,walk

AUTHOR

Alois P. Heinz, Mar 26 2017

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 July 5 01:22 EDT 2020. Contains 335457 sequences. (Running on oeis4.)