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A281206 Number of 2 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 A281206 #8 Feb 18 2019 08:57:09
%S A281206 0,2,14,28,52,94,166,290,502,864,1480,2526,4298,7294,12350,20868,
%T A281206 35196,59262,99630,167258,280422,469576,785424,1312318,2190482,
%U A281206 3652854,6086126,10131820,16853572,28013854,46531510,77237906,128126038,212413104
%N A281206 Number of 2 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 A281206 R. H. Hardin, <a href="/A281206/b281206.txt">Table of n, a(n) for n = 1..210</a>
%F A281206 Empirical: a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + a(n-4) + a(n-5) for n>7.
%F A281206 Empirical g.f.: 2*x^2*(1 + 4*x - 6*x^2 - 6*x^3 + 3*x^4 + 2*x^5) / ((1 - x)*(1 - x - x^2)^2). - _Colin Barker_, Feb 18 2019
%e A281206 Some solutions for n=4:
%e A281206 ..0..0..1..0. .0..1..0..0. .0..0..0..1. .0..0..1..1. .0..0..1..0
%e A281206 ..0..1..0..1. .0..1..1..1. .0..1..0..0. .1..0..1..0. .1..1..0..1
%Y A281206 Row 2 of A281205.
%K A281206 nonn
%O A281206 1,2
%A A281206 _R. H. Hardin_, Jan 17 2017