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%I #6 Apr 20 2021 12:16:50
%S 0,162,16496,1361842,114297392,9617769208,809092017194,68064007019810,
%T 5725825916551386,481680190844257754,40520931584406824770,
%U 3408788505934411237796,286761400254202666052780
%N Number of n X 4 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.
%C Column 4 of A230840.
%H R. H. Hardin, <a href="/A230837/b230837.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=3
%e ..0..2..3..0....0..3..0..1....0..1..0..3....0..1..1..2....0..1..2..3
%e ..1..1..2..1....1..2..3..2....2..0..3..2....3..2..3..0....1..1..0..2
%e ..0..3..2..0....1..0..1..1....3..3..2..1....2..2..1..0....2..3..3..2
%Y Cf. A230840.
%K nonn
%O 1,2
%A _R. H. Hardin_, Oct 31 2013
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