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A198910 Number of nX4 0..7 arrays with values 0..7 introduced in row major order and no element equal to any horizontal or vertical neighbor.

%I A198910 #7 Jul 22 2025 13:07:08
%S A198910 5,500,269940,319608038,481871809749,769126451071174,
%T A198910 1243368053336112649,2015791720035206825303,3270193421121063659774745,
%U A198910 5305976942994216714747844079,8609380449975858170849466245738
%N A198910 Number of nX4 0..7 arrays with values 0..7 introduced in row major order and no element equal to any horizontal or vertical neighbor.
%C A198910 Column 4 of A198914
%H A198910 R. H. Hardin, <a href="/A198910/b198910.txt">Table of n, a(n) for n = 1..123</a>
%F A198910 Empirical: a(n) = 2296*a(n-1) -1239092*a(n-2) +252277904*a(n-3) -24632440060*a(n-4) +1347961370754*a(n-5) -44994493075469*a(n-6) +960046624478492*a(n-7) -13429762946315149*a(n-8) +124540876930445980*a(n-9) -765040702294085198*a(n-10) +3074302608489782520*a(n-11) -7884335188124038674*a(n-12) +12438514719451024794*a(n-13) -11471383995777540513*a(n-14) +5595786642970619820*a(n-15) -1099871574411268404*a(n-16)
%e A198910 Some solutions with values 0 to 7 for n=3
%e A198910 ..0..1..2..3....0..1..0..2....0..1..2..3....0..1..2..1....0..1..0..2
%e A198910 ..3..4..5..2....3..4..5..3....4..5..0..6....3..4..5..6....2..0..3..4
%e A198910 ..6..7..1..6....6..1..7..2....2..7..6..5....4..7..0..7....3..5..6..7
%K A198910 nonn
%O A198910 1,1
%A A198910 _R. H. Hardin_ Oct 31 2011