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A280435 Number of nX3 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 A280435 #6 Jan 04 2017 13:12:34
%S A280435 1,10,21,42,77,136,236,404,687,1162,1959,3294,5528,9262,15497,25898,
%T A280435 43233,72100,120132,199992,332675,552970,918491,1524602,2529072,
%U A280435 4192786,6946941,11503914,19040117,31497472,52080284,86073884,142192983
%N A280435 Number of nX3 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.
%C A280435 Column 3 of A280440.
%H A280435 R. H. Hardin, <a href="/A280435/b280435.txt">Table of n, a(n) for n = 1..210</a>
%F A280435 Empirical: a(n) = 3*a(n-1) -a(n-2) -3*a(n-3) +a(n-4) +a(n-5) for n>6.
%F A280435 Empirical g.f.: x -x^2*(10-9*x-11*x^2+2*x^3) / ( (x-1)*(x^2+x-1)^2 ). - _R. J. Mathar_, Jan 04 2017
%e A280435 Some solutions for n=4
%e A280435 ..0..0..1. .0..1..0. .0..0..1. .0..1..0. .0..1..0. .0..1..0. .0..1..0
%e A280435 ..1..1..0. .1..1..1. .0..1..0. .1..0..1. .1..0..0. .0..1..0. .1..0..1
%e A280435 ..0..0..1. .0..1..0. .1..0..1. .0..1..0. .0..1..0. .1..0..1. .1..1..0
%e A280435 ..1..0..1. .1..0..1. .1..0..1. .0..1..1. .1..0..1. .0..0..1. .1..0..1
%Y A280435 Cf. A280440.
%K A280435 nonn
%O A280435 1,2
%A A280435 _R. H. Hardin_, Jan 03 2017