The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A228679 Number of nX4 binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally. 1

%I

%S 8,40,216,1152,6160,32928,176032,941056,5030848,26894720,143778176,

%T 768632832,4109082880,21967006208,117434808832,627802177536,

%U 3356207397888,17942161561600,95918137153536,512774840614912

%N Number of nX4 binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally.

%C Column 4 of A228683

%H R. H. Hardin, <a href="/A228679/b228679.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) -2*a(n-2) -8*a(n-3).

%F Empirical: G.f. -8*x*(-1+x+x^2) / ( 1-6*x+2*x^2+8*x^3 ). - _R. J. Mathar_, Aug 31 2013

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Aug 30 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 30 22:59 EST 2021. Contains 349426 sequences. (Running on oeis4.)