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!)
A279736 Number of n X 3 0..1 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1

%I #8 Feb 11 2019 14:23:06

%S 2,6,35,168,766,3402,14827,63680,270313,1136546,4740986,19644984,

%T 80939021,331835984,1354628539,5508982340,22328647462,90229615030,

%U 363633214831,1461903606752,5864244756909,23476219277174,93808204087890

%N Number of n X 3 0..1 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%H R. H. Hardin, <a href="/A279736/b279736.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 10*a(n-1) - 35*a(n-2) + 54*a(n-3) - 45*a(n-4) + 20*a(n-5) - 4*a(n-6) for n>7.

%F Empirical g.f.: x*(1 - x)*(1 - 2*x)*(2 - 8*x + 17*x^2 - 13*x^3 + 4*x^4) / (1 - 5*x + 5*x^2 - 2*x^3)^2. - _Colin Barker_, Feb 11 2019

%e Some solutions for n=4:

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

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

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

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

%Y Column 3 of A279741.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 18 2016

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 April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)