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

%I #9 Aug 04 2018 10:35:06

%S 3,35,400,4525,51025,574800,6473175,72891475,820773600,9242002325,

%T 104065684825,1171786908400,13194399201775,148569807813675,

%U 1672905820612800,18837029565221725,212106191270112225

%N Number of n X 2 arrays of occupancy after each element stays put or moves to some king-move neighbor.

%C Column 2 of A221225.

%H R. H. Hardin, <a href="/A221223/b221223.txt">Table of n, a(n) for n = 1..22</a>

%F Empirical: a(n) = 15*a(n-1) - 43*a(n-2) + 10*a(n-3).

%F Empirical g.f.: x*(3 - 10*x + 4*x^2) / (1 - 15*x + 43*x^2 - 10*x^3). - _Colin Barker_, Aug 04 2018

%e Some solutions for n=3:

%e ..0..0....2..0....2..1....2..0....1..3....0..0....3..1....0..0....2..1....2..0

%e ..4..0....2..1....0..0....2..0....0..0....1..2....1..1....5..1....0..1....0..2

%e ..0..2....1..0....1..2....1..1....0..2....3..0....0..0....0..0....2..0....2..0

%Y Cf. A221225.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 05 2013

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 June 24 18:37 EDT 2024. Contains 373688 sequences. (Running on oeis4.)