login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A022444 Number of self-avoiding closed walks (from (0,0) to (0,0)) of length 2n in strip {-1, 0, 1} X Z. 2
1, 0, 8, 16, 44, 112, 252, 564, 1276, 2840, 6220, 13532, 29292, 63024, 134876, 287428, 610268, 1291336, 2724204, 5731500, 12029260, 25191008, 52646908, 109823636, 228707004, 475533432, 987305612, 2047088764, 4239132716 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
REFERENCES
J. Labelle, Self-avoiding walks and polyominoes in strips, Bull. ICA, 23 (1998), 88-98.
LINKS
Sean A. Irvine, Java program (github)
FORMULA
G.f.: (-12*x^7+16*x^6-36*x^5+37*x^4-24*x^3+14*x^2-4*x+1) / ((1+x^2)^2*(1-2*x)^2) (conjectured).
CROSSREFS
Sequence in context: A155110 A245419 A266159 * A089828 A297619 A188825
KEYWORD
nonn,walk,easy
AUTHOR
Jacques Labelle (labelle.jacques(AT)uqam.ca)
EXTENSIONS
a(16)-a(28) and title improved by Sean A. Irvine, May 15 2019
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 14:54 EDT 2024. Contains 371960 sequences. (Running on oeis4.)