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A216333 Number of horizontal and antidiagonal neighbor colorings of the even squares of an nX3 array with new integer colors introduced in row major order.

%I A216333 #6 Jul 22 2025 23:30:38
%S A216333 1,2,15,52,877,4140,115975,678570,27644437,190899322,10480142147,
%T A216333 82864869804,5832742205057,51724158235372,4506715738447323,
%U A216333 44152005855084346,4638590332229999353,49631246523618756274
%N A216333 Number of horizontal and antidiagonal neighbor colorings of the even squares of an nX3 array with new integer colors introduced in row major order.
%C A216333 Column 3 of A216338
%H A216333 R. H. Hardin, <a href="/A216333/b216333.txt">Table of n, a(n) for n = 1..210</a>
%e A216333 Some solutions for n=4
%e A216333 ..0..x..1....0..x..1....0..x..1....0..x..1....0..x..1....0..x..1....0..x..1
%e A216333 ..x..2..x....x..2..x....x..2..x....x..0..x....x..2..x....x..2..x....x..2..x
%e A216333 ..3..x..0....3..x..1....1..x..2....2..x..0....3..x..2....1..x..0....3..x..4
%e A216333 ..x..1..x....x..3..x....x..3..x....x..3..x....x..4..x....x..1..x....x..5..x
%K A216333 nonn
%O A216333 1,2
%A A216333 _R. H. Hardin_ Sep 04 2012