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A183359 One quarter the number of nX7 1..4 arrays with no two neighbors of any element equal to each other.

%I A183359 #7 Jul 22 2025 08:51:33
%S A183359 972,36864,34992,63504,137088,331776,829440,1806336,3852288,8294400,
%T A183359 18137088,40144896,88897536,196448256,433465344,955551744,2106667008,
%U A183359 4645785600,10246588416,22600912896,49849804800,109947949056
%N A183359 One quarter the number of nX7 1..4 arrays with no two neighbors of any element equal to each other.
%C A183359 Column 7 of A183362
%H A183359 R. H. Hardin, <a href="/A183359/b183359.txt">Table of n, a(n) for n = 1..58</a>
%F A183359 Empirical: a(n)=2*a(n-1)+a(n-3)-2*a(n-4)+4*a(n-5)+a(n-6)-a(n-9) for n>14
%e A183359 Some solutions for 5X7 with a(1,1)=1
%e A183359 ..1..1..2..3..1..2..2....1..1..3..4..2..1..1....1..2..3..4..1..1..3
%e A183359 ..2..4..4..3..1..4..4....2..4..3..1..2..4..3....3..2..1..4..3..2..2
%e A183359 ..2..3..1..2..2..3..3....3..4..2..1..3..4..2....3..4..1..2..3..4..4
%e A183359 ..4..3..1..4..4..1..1....3..1..2..4..3..1..2....2..4..3..2..1..1..3
%e A183359 ..4..2..2..3..3..2..2....2..1..3..4..2..1..4....1..1..3..4..4..2..2
%K A183359 nonn
%O A183359 1,1
%A A183359 _R. H. Hardin_ Jan 04 2011