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A280439 Number of n X 7 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%I A280439 #7 Feb 13 2019 11:19:58
%S A280439 20,120,236,386,574,834,1211,1784,2684,4128,6478,10334,16693,27208,
%T A280439 44620,73470,121278,200490,331695,548936,908476,1503260,2486766,
%U A280439 4112326,6797929,11232984,18554156,30634874,50561854,83419218,137578403
%N A280439 Number of n X 7 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
%H A280439 R. H. Hardin, <a href="/A280439/b280439.txt">Table of n, a(n) for n = 1..210</a>
%F A280439 Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>7.
%F A280439 Empirical g.f.: x*(20 + 40*x - 164*x^2 - 38*x^3 + 134*x^4 + 74*x^5 + 19*x^6) / ((1 - x)^2*(1 - x - x^2)^2). - _Colin Barker_, Feb 13 2019
%e A280439 Some solutions for n=4:
%e A280439 ..0..0..1..0..1..0..1. .0..1..1..0..1..0..1. .0..0..1..1..0..0..1
%e A280439 ..1..1..0..1..0..1..0. .0..1..0..1..0..1..0. .1..1..0..0..1..1..0
%e A280439 ..0..0..1..0..1..0..1. .1..0..1..0..1..0..1. .0..0..1..1..0..1..0
%e A280439 ..1..1..0..1..1..0..1. .0..1..0..1..0..1..0. .1..1..0..0..1..0..1
%Y A280439 Column 7 of A280440.
%K A280439 nonn
%O A280439 1,1
%A A280439 _R. H. Hardin_, Jan 03 2017