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%I #7 Mar 15 2023 16:27:06
%S 15,1080,587208,953124784,3410310590912,22727131144960768,
%T 253335104721267417984,4382417290595586402531584,
%U 111319355727036703898865465344,3978834602846298450265688566196224,193442461762324413798952526604793292800
%N Number of n X 4 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).
%H Andrew Howroyd, <a href="/A207980/b207980.txt">Table of n, a(n) for n = 1..140</a>
%e Some solutions for n=4
%e ..0..0..0..0....0..1..0..0....0..0..0..0....0..0..1..0....0..0..0..0
%e ..1..1..2..1....2..1..2..1....1..1..2..1....1..2..1..0....1..1..1..1
%e ..0..3..0..0....0..0..0..0....2..0..0..0....0..0..1..0....2..0..0..0
%e ..4..1..1..1....1..1..1..1....1..1..1..2....2..2..1..0....1..1..1..1
%Y Column 4 of A207981.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 22 2012
%E Terms a(8) and beyond from _Andrew Howroyd_, Mar 15 2023
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