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%I #7 Jul 01 2017 23:00:31
%S 15,1657,426422,450288795,1182700979380,6184248124218800,
%T 56513375910372605548,826725568737937330039810,
%U 18171823971396715681105965282,572057633247843506849301892746850,24840621984533068280588275487942834483,1443495070617319156132945205013820325621405
%N Number of nX4 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors).
%H Andrew Howroyd, <a href="/A208000/b208000.txt">Table of n, a(n) for n = 1..50</a>
%e Some solutions for n=4
%e ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
%e ..1..1..1..1....1..1..1..1....1..1..1..1....1..1..1..2....1..1..1..1
%e ..2..2..2..3....2..2..2..2....2..2..2..2....2..1..2..2....2..2..2..2
%e ..0..0..0..0....0..0..0..0....3..3..0..0....0..0..3..4....0..0..3..0
%Y Column 4 of A208001.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 22 2012
%E Terms a(6) and beyond from _Andrew Howroyd_, Jul 01 2017
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