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A281207 Number of 3 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 A281207 #8 Feb 18 2019 06:50:34
%S A281207 0,10,56,98,176,310,537,922,1573,2672,4524,7640,12875,21658,36375,
%T A281207 61006,102184,170954,285693,476954,795497,1325596,2207076,3671788,
%U A281207 6103951,10139930,16833147,27926522,46302368,76725022,127066209,210326170
%N A281207 Number of 3 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 A281207 R. H. Hardin, <a href="/A281207/b281207.txt">Table of n, a(n) for n = 1..210</a>
%F A281207 Empirical: a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + a(n-4) + a(n-5) for n>8.
%F A281207 Empirical g.f.: x^2*(10 + 26*x - 60*x^2 - 32*x^3 + 38*x^4 + 11*x^5 - 5*x^6) / ((1 - x)*(1 - x - x^2)^2). - _Colin Barker_, Feb 18 2019
%e A281207 Some solutions for n=4:
%e A281207 ..0..0..1..0. .0..1..1..1. .0..0..1..0. .0..1..0..1. .0..1..0..1
%e A281207 ..1..0..1..0. .0..1..0..1. .1..1..1..0. .1..0..1..0. .1..0..1..0
%e A281207 ..1..0..0..1. .0..1..0..1. .0..0..1..0. .1..0..0..0. .1..0..0..1
%Y A281207 Row 3 of A281205.
%K A281207 nonn
%O A281207 1,2
%A A281207 _R. H. Hardin_, Jan 17 2017