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A222872 Number of nX2 0..3 arrays with no more than floor(nX2/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.

%I A222872 #7 Jul 23 2025 03:11:17
%S A222872 1,11,131,2150,32491,533186,8362152,135650378,2155759835,34780282521,
%T A222872 555913562689,8947148045345,143379589806584,2305060329759954,
%U A222872 36982483115935396,594232174227590798,9538759468134692551
%N A222872 Number of nX2 0..3 arrays with no more than floor(nX2/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.
%C A222872 Column 2 of A222878
%H A222872 R. H. Hardin, <a href="/A222872/b222872.txt">Table of n, a(n) for n = 1..210</a>
%e A222872 Some solutions for n=3
%e A222872 ..0..1....0..1....0..1....0..1....0..0....0..1....0..1....0..1....0..1....0..1
%e A222872 ..2..1....2..2....0..2....0..0....1..0....0..2....1..0....0..1....2..1....2..1
%e A222872 ..1..2....1..0....0..1....0..1....2..3....3..1....2..0....2..3....3..1....0..0
%K A222872 nonn
%O A222872 1,2
%A A222872 _R. H. Hardin_ Mar 08 2013