The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A268882 Number of n X 4 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. 1

%I

%S 5,54,501,4133,31956,236960,1706732,12034000,83485488,571836176,

%T 3876692480,26059576704,173934499008,1153927868416,7615733792000,

%U 50035609197824,327432063642624,2135189929320448,13880060602788864

%N Number of n X 4 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

%H R. H. Hardin, <a href="/A268882/b268882.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 16*a(n-1) - 88*a(n-2) + 200*a(n-3) - 208*a(n-4) + 96*a(n-5) - 16*a(n-6) for n>7.

%F Empirical g.f.: x*(5 - 26*x + 77*x^2 - 131*x^3 + 156*x^4 - 80*x^5 + 4*x^6) / (1 - 8*x + 12*x^2 - 4*x^3)^2. - _Colin Barker_, Jan 15 2019

%e Some solutions for n=4:

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

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

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

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

%Y Column 4 of A268886.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 15 2016

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 January 19 06:18 EST 2022. Contains 350464 sequences. (Running on oeis4.)