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A280553 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 two elements, and with new values introduced in order 0 sequentially upwards.

%I A280553 #9 Feb 13 2019 16:56:27
%S A280553 13,400,1316,3182,6386,11697,20334,34360,57389,95548,159360,266756,
%T A280553 448302,755986,1278112,2164458,3668734,6220179,10544150,17865068,
%U A280553 30247639,51170104,86486508,146040766,246372038,415246118,699240242
%N A280553 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 two elements, and with new values introduced in order 0 sequentially upwards.
%H A280553 R. H. Hardin, <a href="/A280553/b280553.txt">Table of n, a(n) for n = 1..210</a>
%F A280553 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>12.
%F A280553 Empirical g.f.: x*(13 + 322*x - 928*x^2 + 21*x^3 + 930*x^4 + 341*x^5 - 79*x^6 - 480*x^7 - 148*x^8 - 205*x^9 - 238*x^10 + 6*x^11) / ((1 - x)^3*(1 - x - x^2)^3). - _Colin Barker_, Feb 13 2019
%e A280553 Some solutions for n=4:
%e A280553 ..0..1..1..1..0..1..0. .0..1..0..1..0..1..0. .0..0..1..0..1..1..0
%e A280553 ..0..0..1..0..1..0..1. .0..1..0..1..0..1..1. .1..1..0..1..0..0..1
%e A280553 ..0..1..0..1..0..1..0. .1..0..1..0..1..0..0. .0..0..1..0..1..1..1
%e A280553 ..1..0..1..0..1..0..1. .0..0..0..1..0..1..1. .1..1..0..1..0..0..1
%Y A280553 Column 7 of A280554.
%K A280553 nonn
%O A280553 1,1
%A A280553 _R. H. Hardin_, Jan 05 2017