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A281208 Number of 4 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%I A281208 #8 Feb 18 2019 06:46:04
%S A281208 0,38,168,270,470,804,1358,2284,3834,6432,10786,18080,30290,50712,
%T A281208 84838,141812,236846,395228,658966,1097796,1827410,3039624,5052282,
%U A281208 8391768,13929370,23106544,38306878,63470044,105104774,173959572,287777246
%N A281208 Number of 4 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
%H A281208 R. H. Hardin, <a href="/A281208/b281208.txt">Table of n, a(n) for n = 1..210</a>
%F A281208 Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>10.
%F A281208 Empirical g.f.: 2*x^2*(19 + 8*x - 125*x^2 + 69*x^3 + 94*x^4 - 55*x^5 - 17*x^6 + 13*x^7 + x^8) / ((1 - x)^2*(1 - x - x^2)^2). - _Colin Barker_, Feb 18 2019
%e A281208 Some solutions for n=4:
%e A281208 ..0..0..0..1. .0..0..0..1. .0..0..1..0. .0..1..1..0. .0..0..1..0
%e A281208 ..0..1..0..0. .1..1..0..0. .1..0..1..1. .0..0..1..1. .0..1..0..1
%e A281208 ..0..1..1..0. .0..1..1..0. .1..0..0..1. .1..0..0..1. .0..1..0..1
%e A281208 ..0..0..1..1. .0..0..1..0. .1..0..1..0. .1..0..1..0. .0..1..0..1
%Y A281208 Row 4 of A281205.
%K A281208 nonn
%O A281208 1,2
%A A281208 _R. H. Hardin_, Jan 17 2017