A279129 - OEIS

A279129

Number of nX3 0..1 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%I #4 Dec 06 2016 18:57:14

%S 0,9,66,256,820,2551,7491,21131,57971,155551,409876,1064002,2727560,

%T 6917391,17381168,43320628,107203164,263611545,644549767,1567944409,

%U 3796630655,9154650571,21989697066,52634342562,125577952504,298716701553

%N Number of nX3 0..1 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%C Column 3 of A279134.

%H R. H. Hardin, <a href="/A279129/b279129.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) -11*a(n-2) +5*a(n-3) +a(n-5) +9*a(n-6) -6*a(n-7) +3*a(n-8) -5*a(n-9) -a(n-11) for n>17

%e Some solutions for n=4

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

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

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

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

%Y Cf. A279134.

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 06 2016