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!)
A233157 Number of 4 X n 0..2 arrays with no element x(i,j) adjacent to value 2-x(i,j) horizontally or antidiagonally. 1

%I #8 Oct 09 2018 14:57:30

%S 81,384,2592,17496,121176,842616,5871528,40931568,285366888,

%T 1989557640,13871104848,96708780360,674249796360,4700843090928,

%U 32774093555112,228499694410248,1593090904911120,11106967289377032,77437340197187976

%N Number of 4 X n 0..2 arrays with no element x(i,j) adjacent to value 2-x(i,j) horizontally or antidiagonally.

%H R. H. Hardin, <a href="/A233157/b233157.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-1) - 15*a(n-2) + 6*a(n-3) for n>7.

%F Empirical g.f.: 3*x*(27 - 115*x + 117*x^2 - 186*x^3 + 96*x^4 - 360*x^5 + 216*x^6) / (1 - 9*x + 15*x^2 - 6*x^3). - _Colin Barker_, Oct 09 2018

%e Some solutions for n=5:

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

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

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

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

%Y Row 4 of A233155.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 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 13 05:35 EDT 2024. Contains 373366 sequences. (Running on oeis4.)