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!)
A208288 Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically. 1

%I

%S 8,64,216,984,3984,16872,70216,294192,1229400,5142728,21504256,

%T 89933368,376090120,1572797488,6577333928,27506063752,115028758000,

%U 481043815944,2011697870456,8412806681456,35181880551080,147128631386264

%N Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

%C Row 4 of A208287.

%H R. H. Hardin, <a href="/A208288/b208288.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) + 6*a(n-2) - 4*a(n-3) - 2*a(n-4) + a(n-5).

%F Empirical g.f.: 8*x*(1 + 5*x - 3*x^2 - 2*x^3 + x^4) / ((1 + x - x^2)*(1 - 4*x - x^2 + x^3)). - _Colin Barker_, Jun 30 2018

%e Some solutions for n=4:

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

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

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

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

%Y Cf. A208287.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 25 2012

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 27 22:39 EDT 2022. Contains 354110 sequences. (Running on oeis4.)