The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A221223 Number of n X 2 arrays of occupancy after each element stays put or moves to some king-move neighbor. 1
3, 35, 400, 4525, 51025, 574800, 6473175, 72891475, 820773600, 9242002325, 104065684825, 1171786908400, 13194399201775, 148569807813675, 1672905820612800, 18837029565221725, 212106191270112225 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A221225.
LINKS
FORMULA
Empirical: a(n) = 15*a(n-1) - 43*a(n-2) + 10*a(n-3).
Empirical g.f.: x*(3 - 10*x + 4*x^2) / (1 - 15*x + 43*x^2 - 10*x^3). - Colin Barker, Aug 04 2018
EXAMPLE
Some solutions for n=3:
..0..0....2..0....2..1....2..0....1..3....0..0....3..1....0..0....2..1....2..0
..4..0....2..1....0..0....2..0....0..0....1..2....1..1....5..1....0..1....0..2
..0..2....1..0....1..2....1..1....0..2....3..0....0..0....0..0....2..0....2..0
CROSSREFS
Cf. A221225.
Sequence in context: A086043 A221774 A221687 * A006767 A065929 A161495
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2013
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 May 23 05:11 EDT 2024. Contains 372758 sequences. (Running on oeis4.)