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A240461 Number of 2 X n 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.

%I A240461 #8 Oct 29 2018 05:03:34
%S A240461 5,21,89,375,1583,6685,28241,119319,504151,2130189,9000729,38030999,
%T A240461 160693343,678981661,2868918401,12122113399,51219871687,216420616013,
%U A240461 914447487881,3863838035639,16325972308111,68982542575773
%N A240461 Number of 2 X n 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.
%H A240461 R. H. Hardin, <a href="/A240461/b240461.txt">Table of n, a(n) for n = 1..210</a>
%F A240461 Empirical: a(n) = 6*a(n-1) - 7*a(n-2) - 4*a(n-3) + 8*a(n-4).
%F A240461 Empirical g.f.: x*(5 - 9*x - 2*x^2 + 8*x^3) / (1 - 6*x + 7*x^2 + 4*x^3 - 8*x^4). - _Colin Barker_, Oct 29 2018
%e A240461 Some solutions for n=4:
%e A240461 ..2..2..2..0....0..2..0..2....0..2..0..2....2..2..2..0....0..0..0..0
%e A240461 ..2..2..2..0....0..3..1..3....0..0..2..0....2..2..2..1....2..2..0..0
%Y A240461 Row 2 of A240460.
%K A240461 nonn
%O A240461 1,1
%A A240461 _R. H. Hardin_, Apr 05 2014