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A221931 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out straight through or left turns.

%I A221931 #6 Jul 23 2025 02:20:34
%S A221931 1,184,5748,201378,6888458,236114556,8089630790,277061308667,
%T A221931 9488649958342,324954778576668,11128548401493743,381112186997579115,
%U A221931 13051688407062314783,446972092491243621991,15307140370408977681367
%N A221931 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out straight through or left turns.
%C A221931 Row 3 of A221929
%H A221931 R. H. Hardin, <a href="/A221931/b221931.txt">Table of n, a(n) for n = 1..47</a>
%e A221931 Some solutions for n=3
%e A221931 ..0..0..0....1..2..0....1..2..0....0..0..0....0..5..0....1..0..0....1..3..1
%e A221931 ..2..4..1....2..1..2....0..1..2....1..4..2....1..2..0....2..2..0....0..0..0
%e A221931 ..2..0..0....0..0..1....1..0..2....1..1..0....1..0..0....0..4..0....2..0..2
%K A221931 nonn
%O A221931 1,2
%A A221931 _R. H. Hardin_ Feb 01 2013