A222285 - OEIS

%I #8 Oct 03 2025 20:15:58

%S 0,4,4,35,83,532,1427,8540,23798,143594,405187,2455279,6993039,

%T 42590466,121981025,745909396,2145554406,13161790760,37983541068,

%U 233613349710,675981684148,4166412530876,12082238135283,74601934076542

%N Number of nX3 0..1 arrays with exactly floor(nX3/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..1 order.

%C Column 3 of A222290

%H R. H. Hardin, <a href="/A222285/b222285.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 14 2013