cp's OEIS Frontend

A269054 Number of 3 X n 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two not more than once.

%I A269054 #7 Jan 18 2019 15:06:53
%S A269054 27,174,594,3078,13140,58752,253416,1090344,4637904,19604352,82332384,
%T A269054 343986912,1430547456,5925418752,24456120000,100618925568,
%U A269054 412797979584,1689208728576,6896384506176,28095875422848,114241910041536
%N A269054 Number of 3 X n 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two not more than once.
%H A269054 R. H. Hardin, <a href="/A269054/b269054.txt">Table of n, a(n) for n = 1..210</a>
%F A269054 Empirical: a(n) = 6*a(n-1) - a(n-2) - 28*a(n-3) - 4*a(n-4) + 16*a(n-5) - 4*a(n-6) for n>8.
%F A269054 Empirical g.f.: 3*x*(9 + 4*x - 141*x^2 + 148*x^3 + 82*x^4 - 38*x^5 - 24*x^6 + 8*x^7) / (1 - 3*x - 4*x^2 + 2*x^3)^2. - _Colin Barker_, Jan 18 2019
%e A269054 Some solutions for n=4:
%e A269054 ..2..2..1..1. .0..1..2..2. .0..1..0..1. .2..2..1..2. .1..1..2..1
%e A269054 ..2..2..2..2. .0..1..0..1. .0..0..0..1. .2..2..1..2. .2..2..2..2
%e A269054 ..1..2..1..2. .2..1..2..1. .1..1..0..0. .2..2..2..1. .1..2..1..2
%Y A269054 Row 3 of A269052.
%K A269054 nonn
%O A269054 1,1
%A A269054 _R. H. Hardin_, Feb 18 2016