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A281062 Number of 7Xn 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%I A281062 #4 Jan 13 2017 17:03:24
%S A281062 0,1686,15028,27635,58005,119205,221212,394884,689397,1191475,2050466,
%T A281062 3523654,6051629,10389370,17827528,30568529,52364160,89595493,
%U A281062 153099429,261254732,445190263,757565887,1287362382,2184769552,3703030677
%N A281062 Number of 7Xn 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
%C A281062 Row 7 of A281056.
%H A281062 R. H. Hardin, <a href="/A281062/b281062.txt">Table of n, a(n) for n = 1..210</a>
%F A281062 Empirical: a(n) = 6*a(n-1) -12*a(n-2) +5*a(n-3) +12*a(n-4) -12*a(n-5) -3*a(n-6) +6*a(n-7) -a(n-9) for n>20
%e A281062 Some solutions for n=4
%e A281062 ..0..1..1..0. .0..1..1..0. .0..1..0..1. .0..0..0..1. .0..1..0..1
%e A281062 ..0..0..1..0. .1..0..1..0. .0..1..1..0. .1..1..0..1. .0..1..0..1
%e A281062 ..1..1..0..1. .1..0..1..0. .0..1..0..1. .0..1..0..1. .0..1..0..0
%e A281062 ..0..1..0..1. .0..1..0..1. .0..1..0..0. .0..1..0..1. .0..1..1..0
%e A281062 ..1..0..1..0. .0..1..0..1. .1..0..1..1. .0..1..0..0. .0..0..1..0
%e A281062 ..1..0..1..0. .1..0..0..1. .1..0..0..1. .1..0..1..1. .1..0..1..0
%e A281062 ..0..0..1..0. .0..1..0..1. .1..1..0..1. .1..0..0..1. .1..1..0..0
%Y A281062 Cf. A281056.
%K A281062 nonn
%O A281062 1,2
%A A281062 _R. H. Hardin_, Jan 13 2017