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!)
A196316 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 1,3,0,2,4 for x=0,1,2,3,4. 7

%I #8 Feb 18 2018 10:02:29

%S 1,7,10,23,57,122,275,623,1394,3133,7045,15824,35557,79901,179530,

%T 403401,906439,2036744,4576523,10283359,23106492,51919817,116662775,

%U 262138870,589020695,1323517493,2973916806,6682330407,15015060135,33738533866

%N Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 1,3,0,2,4 for x=0,1,2,3,4.

%C Every 0 is next to 0 1's, every 1 is next to 1 3's, every 2 is next to 2 0's, every 3 is next to 3 2's, every 4 is next to 4 4's.

%C Column 2 of A196322.

%H R. H. Hardin, <a href="/A196316/b196316.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = a(n-1) +2*a(n-2) +2*a(n-3) -a(n-5).

%F Empirical g.f.: x*(1 + 6*x + x^2 - 3*x^3) / ((1 + x + x^2)*(1 - 2*x - x^2 + x^3)). - _Colin Barker_, Feb 18 2018

%e Some solutions for n=4:

%e ..0..0....2..0....0..2....0..0....0..2....0..0....0..0....0..2....0..0....0..2

%e ..0..2....0..2....2..0....0..0....0..0....0..0....0..2....0..0....2..2....0..0

%e ..0..2....0..2....2..0....0..0....0..0....0..0....0..2....0..0....0..0....0..0

%e ..2..0....0..0....0..2....0..2....0..2....2..0....0..0....0..0....2..0....2..0

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 01 2011

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 26 09:40 EDT 2024. Contains 372824 sequences. (Running on oeis4.)