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A198978 Number of nX4 0..5 arrays with values 0..5 introduced in row major order and no element equal to any horizontal or vertical neighbor.

%I A198978 #7 Jul 22 2025 13:07:36
%S A198978 5,481,146286,53082012,19622872903,7267830860056,2692353648978984,
%T A198978 997397244990907738,369492074075459555844,136880688981914387733120,
%U A198978 50708322978926251631508008,18785221234054066344117511329
%N A198978 Number of nX4 0..5 arrays with values 0..5 introduced in row major order and no element equal to any horizontal or vertical neighbor.
%C A198978 Column 4 of A198982
%H A198978 R. H. Hardin, <a href="/A198978/b198978.txt">Table of n, a(n) for n = 1..200</a>
%F A198978 Empirical: a(n) = 454*a(n-1) -33435*a(n-2) +955655*a(n-3) -13146749*a(n-4) +95351613*a(n-5) -373512375*a(n-6) +780821577*a(n-7) -866661210*a(n-8) +478426797*a(n-9) -102202326*a(n-10)
%e A198978 Some solutions with all values from 0 to 5 for n=5
%e A198978 ..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
%e A198978 ..1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0
%e A198978 ..2..3..0..1....2..3..0..1....2..3..0..1....2..3..0..1....2..1..0..3
%e A198978 ..0..4..3..5....0..1..4..3....4..1..5..3....4..5..4..3....0..3..4..2
%e A198978 ..1..5..2..1....4..5..3..1....5..3..4..0....3..4..5..0....5..2..3..0
%K A198978 nonn
%O A198978 1,1
%A A198978 _R. H. Hardin_ Nov 01 2011