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A207399 Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically.

%I A207399 #8 Mar 05 2018 05:36:08
%S A207399 9,81,289,729,1521,2809,4761,7569,11449,16641,23409,32041,42849,56169,
%T A207399 72361,91809,114921,142129,173889,210681,253009,301401,356409,418609,
%U A207399 488601,567009,654481,751689,859329,978121,1108809,1252161,1408969
%N A207399 Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically.
%C A207399 Column 4 of A207403.
%H A207399 R. H. Hardin, <a href="/A207399/b207399.txt">Table of n, a(n) for n = 1..210</a>
%F A207399 Empirical: a(n) = n^4 + 6*n^3 + 7*n^2 - 6*n + 1.
%F A207399 Conjectures from _Colin Barker_, Mar 05 2018: (Start)
%F A207399 G.f.: x*(9 + 36*x - 26*x^2 + 4*x^3 + x^4) / (1 - x)^5.
%F A207399 a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
%F A207399 (End)
%e A207399 Some solutions for n=4:
%e A207399 ..1..1..1..1....0..0..0..0....1..0..1..0....1..0..0..0....1..1..0..1
%e A207399 ..1..1..1..1....0..0..0..0....1..1..1..1....0..1..0..0....0..0..0..0
%e A207399 ..1..1..1..1....0..0..0..0....1..1..1..1....1..0..0..0....0..1..0..1
%e A207399 ..1..1..1..1....0..0..0..0....1..1..1..1....1..1..0..0....0..0..0..0
%Y A207399 Cf. A207403.
%K A207399 nonn
%O A207399 1,1
%A A207399 _R. H. Hardin_, Feb 17 2012