A222987 - OEIS

%I #4 Mar 11 2013 06:24:47

%S 2,4,7,25,86,332,1172,4566,16562,64718,238856,933970,3493494,13656426,

%T 51627746,201696470,768828322,3002421486,11518434130,44975259758,

%U 173404040458,677168068918,2621003912178,10238867982150,39750857800978

%N Number of 2Xn 0..2 arrays with no more than floor(2Xn/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..2 order

%C Row 2 of A222986

%H R. H. Hardin, <a href="/A222987/b222987.txt">Table of n, a(n) for n = 1..88</a>

%e All solutions for n=3

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 11 2013