A241364 - OEIS

%I #8 Oct 30 2018 05:20:18

%S 1,7,47,326,2284,16026,112458,789166,5537942,38862302,272714782,

%T 1913766030,13429783278,94243014094,661346912462,4640977825550,

%U 32567892540814,228543997497870,1603799162836494,11254602102332686

%N Number of n X 2 0..2 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order.

%H R. H. Hardin, <a href="/A241364/b241364.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) + 2*a(n-3) - 8*a(n-4) for n>5.

%F Empirical g.f.: x*(1 + x)*(1 - x - x^2 - 4*x^3) / ((1 - x)*(1 - 6*x - 6*x^2 - 8*x^3)). - _Colin Barker_, Oct 30 2018

%e Some solutions for n=4:

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

%e ..1..2....0..1....2..0....0..2....1..1....0..2....0..1....0..0....1..0....0..0

%e ..2..0....1..0....0..0....2..1....1..0....1..0....0..2....2..0....0..1....0..1

%e ..1..2....1..0....0..1....2..1....1..2....1..2....1..0....2..0....0..2....0..2

%Y Column 2 of A241370.

%K nonn

%O 1,2

%A _R. H. Hardin_, Apr 20 2014