A280475 - OEIS

%I #4 Jan 04 2017 06:23:54

%S 0,22,208,1939,17406,149057,1224092,9717407,75078490,567486429,

%T 4212636472,30802884219,222362166198,1587624277241,11227499711316,

%U 78737492563415,548110879578258,3790518591777685,26059838687117808

%N Number of nX3 0..2 arrays with no element unequal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%C Column 3 of A280480.

%H R. H. Hardin, <a href="/A280475/b280475.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 27*a(n-1) -303*a(n-2) +1857*a(n-3) -6924*a(n-4) +16608*a(n-5) -26048*a(n-6) +26112*a(n-7) -15360*a(n-8) +4096*a(n-9) for n>10

%e Some solutions for n=4

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

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

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

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

%Y Cf. A280480.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 04 2017