A268887 - OEIS

%I #7 Jan 15 2019 17:31:47

%S 0,5,14,54,158,475,1340,3740,10204,27521,73354,193842,508346,1324791,

%T 3433720,8858104,22757432,58253885,148634502,378142446,959527766,

%U 2429034323,6135877428,15469187604,38929330452,97806402617,245354321666

%N Number of 2 X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

%H R. H. Hardin, <a href="/A268887/b268887.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) + 5*a(n-2) - 4*a(n-3) - 11*a(n-4) - 6*a(n-5) - a(n-6).

%F Empirical g.f.: x^2*(5 + 4*x + x^2) / ((1 + x)^2*(1 - 2*x - x^2)^2). - _Colin Barker_, Jan 15 2019

%e Some solutions for n=4:

%e ..1..0..1..1. .1..1..0..0. .0..0..0..1. .1..0..0..0. .1..0..1..0

%e ..1..0..0..0. .0..1..0..1. .1..1..0..0. .0..1..1..0. .0..1..0..0

%Y Row 2 of A268886.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 15 2016