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%I #8 Nov 28 2018 08:03:59
%S 22,71,219,701,2193,6980,21966,69681,219860,696284,2199557,6960357,
%T 21999804,69591126,220014756,695843558,2200194145,6958021138,
%U 22001843859,69577286765,220014836192,695749296057,2200100105526,6957283657381
%N Number of (n+1) X (2+1) 0..1 arrays with every 2 X 2 subblock having a single 1 or two 1s on the same edge or main diagonally.
%H R. H. Hardin, <a href="/A251286/b251286.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + 7*a(n-2) - 9*a(n-3) - 7*a(n-4) + 7*a(n-5) for n>6.
%F Empirical g.f.: x*(22 + 27*x - 77*x^2 - 36*x^3 + 51*x^4 + x^5) / (1 - 2*x - 7*x^2 + 9*x^3 + 7*x^4 - 7*x^5). - _Colin Barker_, Nov 28 2018
%e Some solutions for n=4:
%e ..0..1..1....1..1..0....1..1..1....0..0..1....0..0..0....1..1..1....1..1..1
%e ..0..0..0....0..0..0....0..0..0....1..0..0....0..1..0....0..0..0....0..0..0
%e ..1..0..1....0..1..0....1..1..0....0..1..0....0..0..1....1..1..0....0..1..1
%e ..1..0..1....0..0..0....0..0..0....0..0..1....1..0..0....0..0..1....0..0..0
%e ..1..0..0....0..1..1....0..1..0....1..0..0....0..1..1....1..0..0....1..1..1
%Y Column 2 of A251292.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 01 2014
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