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A222825 Number of nX2 0..3 arrays with no more than floor(nX2/2) elements equal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..3 order.

%I A222825 #7 Jul 23 2025 03:06:26
%S A222825 1,8,80,1154,14388,200082,2652496,36622104,498427856,6893943128,
%T A222825 95040804864,1319624517920,18325966197056,255430185200544,
%U A222825 3564132957005568,49841772120587648,697848234833263872
%N A222825 Number of nX2 0..3 arrays with no more than floor(nX2/2) elements equal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..3 order.
%C A222825 Column 2 of A222828
%H A222825 R. H. Hardin, <a href="/A222825/b222825.txt">Table of n, a(n) for n = 1..209</a>
%e A222825 Some solutions for n=3
%e A222825 ..0..0....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1
%e A222825 ..1..2....2..1....0..2....0..0....0..2....2..3....2..2....2..0....1..0....2..3
%e A222825 ..3..0....0..3....3..1....1..2....1..0....3..2....3..1....1..3....2..1....0..0
%K A222825 nonn
%O A222825 1,2
%A A222825 _R. H. Hardin_ Mar 06 2013