cp's OEIS Frontend

A275498 Number of n X 2 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.

%I A275498 #8 Feb 04 2019 09:08:49
%S A275498 2,9,16,28,56,104,200,380,724,1380,2628,5008,9540,18176,34628,65972,
%T A275498 125688,239456,456204,869144,1655864,3154696,6010220,11450468,
%U A275498 21815044,41561284,79181152,150853252,287400512,547545732,1043165604,1987403816
%N A275498 Number of n X 2 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.
%H A275498 R. H. Hardin, <a href="/A275498/b275498.txt">Table of n, a(n) for n = 1..210</a>
%F A275498 Empirical: a(n) = a(n-1) + 2*a(n-2) - a(n-4) for n>6.
%F A275498 Empirical g.f.: x*(2 + 7*x + 3*x^2 - 6*x^3 - 2*x^4 + x^5) / (1 - x - 2*x^2 + x^4). - _Colin Barker_, Feb 04 2019
%e A275498 Some solutions for n=4:
%e A275498 ..0..1. .0..0. .0..0. .0..0. .0..1. .0..1. .0..1. .0..0. .0..0. .0..0
%e A275498 ..1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .0..1. .0..1. .0..1
%e A275498 ..2..2. .1..2. .1..2. .2..2. .2..2. .1..2. .1..2. .1..2. .1..2. .1..1
%e A275498 ..0..0. .2..2. .2..0. .2..0. .2..0. .2..0. .0..0. .2..2. .1..2. .1..2
%Y A275498 Column 2 of A275504.
%K A275498 nonn
%O A275498 1,1
%A A275498 _R. H. Hardin_, Jul 30 2016