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A240784 Number of 3 X n 0..1 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..1 introduced in row major order.

%I A240784 #8 Oct 29 2018 06:43:09
%S A240784 4,11,20,46,97,216,472,1043,2296,5066,11169,24636,54332,119835,264300,
%T A240784 582934,1285697,2835696,6254320,13794339,30424368,67103058,148000449,
%U A240784 326425268,719953588,1587907627,3502240516,7724434622,17036776865
%N A240784 Number of 3 X n 0..1 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..1 introduced in row major order.
%H A240784 R. H. Hardin, <a href="/A240784/b240784.txt">Table of n, a(n) for n = 1..210</a>
%F A240784 Empirical: a(n) = 2*a(n-1) + a(n-2) - a(n-3) - a(n-5).
%F A240784 Empirical g.f.: x*(4 + 3*x - 6*x^2 - x^3 - 4*x^4) / ((1 - x)*(1 + x)*(1 - 2*x - x^3)). - _Colin Barker_, Oct 29 2018
%e A240784 Some solutions for n=4:
%e A240784 ..0..0..1..1....0..1..0..1....0..0..1..1....0..0..1..0....0..1..0..0
%e A240784 ..0..0..1..1....1..0..0..1....0..0..1..1....0..0..1..0....1..0..0..0
%e A240784 ..1..0..1..1....1..0..0..1....0..1..0..1....0..0..1..0....1..0..0..1
%Y A240784 Row 3 of A240783.
%K A240784 nonn
%O A240784 1,1
%A A240784 _R. H. Hardin_, Apr 12 2014