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A251147 Number of (n+1) X (6+1) 0..2 arrays with every 2 X 2 subblock summing to 4 and no 2 X 2 subblock having exactly two nonzero entries.

%I A251147 #15 Nov 26 2018 17:03:52
%S A251147 427,565,777,1141,1743,2763,4491,7453,12569,21501,37255,65355,116035,
%T A251147 208469,378889,696357,1293471,2426507,4593563,8767469,16856057,
%U A251147 32613805,63450647,124026251,243400723,479274853,946371561,1873038613,3714194799
%N A251147 Number of (n+1) X (6+1) 0..2 arrays with every 2 X 2 subblock summing to 4 and no 2 X 2 subblock having exactly two nonzero entries.
%H A251147 R. H. Hardin, <a href="/A251147/b251147.txt">Table of n, a(n) for n = 1..210</a>
%F A251147 Empirical: a(n) = 3*a(n-1) - 5*a(n-3) + a(n-4) + 2*a(n-5).
%F A251147 Empirical g.f.: x*(427 - 716*x - 918*x^2 + 945*x^3 + 718*x^4) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - x - x^2)). - _Colin Barker_, Nov 26 2018
%e A251147 Some solutions for n=4:
%e A251147 ..0..2..0..2..1..2..1....1..2..0..1..0..1..0....0..2..0..2..1..2..1
%e A251147 ..1..1..1..1..0..1..0....0..1..1..2..1..2..1....1..1..1..1..0..1..0
%e A251147 ..1..1..1..1..2..1..2....2..1..1..0..1..0..1....1..1..1..1..2..1..2
%e A251147 ..1..1..1..1..0..1..0....1..0..2..1..2..1..2....1..1..1..1..0..1..0
%e A251147 ..1..1..1..1..2..1..2....2..1..1..0..1..0..1....0..2..0..2..1..2..1
%Y A251147 Column 6 of A251149.
%K A251147 nonn
%O A251147 1,1
%A A251147 _R. H. Hardin_, Nov 30 2014