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%I #7 Oct 03 2018 06:19:18
%S 15,87,602,3985,26713,178484,1193537,7979619,53352090,356709629,
%T 2384952501,15945724308,106612681357,712809462455,4765824578786,
%U 31864172723641,213042987115297,1424399583243252,9523496644232169
%N Number of (n+1) X (2+1) 0..1 arrays with every element equal to some horizontal, diagonal or antidiagonal neighbor, with top left element zero.
%H R. H. Hardin, <a href="/A232070/b232070.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) + 11*a(n-2) + 2*a(n-3) - 8*a(n-5).
%F Empirical g.f.: x*(15 + 12*x + 2*x^2 - 12*x^3 - 8*x^4) / (1 - 5*x - 11*x^2 - 2*x^3 + 8*x^5). - _Colin Barker_, Oct 03 2018
%e Some solutions for n=6:
%e ..0..0..0....0..1..0....0..1..0....0..0..0....0..1..0....0..0..0....0..0..0
%e ..1..1..0....1..0..0....0..0..1....1..1..0....0..0..1....0..1..0....1..0..0
%e ..0..1..1....0..0..0....0..1..1....1..0..0....0..0..0....1..0..0....1..1..1
%e ..1..0..1....0..0..0....1..0..1....1..1..1....1..1..0....0..1..0....0..0..0
%e ..0..1..0....0..1..0....1..0..0....1..1..1....0..0..0....1..1..1....1..0..1
%e ..0..1..0....1..0..1....1..1..1....0..0..0....1..0..0....0..0..1....1..1..0
%e ..1..0..1....1..1..0....0..0..0....0..0..0....0..1..1....0..1..0....1..1..1
%Y Column 2 of A232076.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 17 2013
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