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A216609 Number of horizontal, diagonal and antidiagonal neighbor colorings of the odd squares of an nX3 array with new integer colors introduced in row major order.

%I A216609 #6 Jul 22 2025 23:33:02
%S A216609 1,1,2,20,67,1335,6097,192713,1094076,49055292,329588907,19602119017,
%T A216609 151146594991,11399696350555,98774751736976,9146845346099410,
%U A216609 87700687826082507,9731199828137067515,102042888281439150263
%N A216609 Number of horizontal, diagonal and antidiagonal neighbor colorings of the odd squares of an nX3 array with new integer colors introduced in row major order.
%C A216609 Column 3 of A216612
%H A216609 R. H. Hardin, <a href="/A216609/b216609.txt">Table of n, a(n) for n = 1..97</a>
%e A216609 Some solutions for n=4
%e A216609 ..x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x
%e A216609 ..1..x..2....1..x..2....1..x..2....1..x..2....1..x..2....1..x..2....1..x..2
%e A216609 ..x..3..x....x..3..x....x..3..x....x..0..x....x..3..x....x..0..x....x..0..x
%e A216609 ..4..x..1....0..x..1....0..x..4....3..x..1....4..x..0....2..x..3....1..x..2
%K A216609 nonn
%O A216609 1,3
%A A216609 _R. H. Hardin_ Sep 10 2012