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A222836 Number of nX6 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order.

%I A222836 #6 Jul 23 2025 03:07:58
%S A222836 55,1536,1944,4056,9600,24576,55296,124416,279936,645504,1476096,
%T A222836 3393024,7742976,17750400,40560000,92952576,212557824,486864384,
%U A222836 1113680256,2550116736,5834651136,13357979136,30567200256,69973632384,160134620544
%N A222836 Number of nX6 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order.
%C A222836 Column 6 of A222838
%H A222836 R. H. Hardin, <a href="/A222836/b222836.txt">Table of n, a(n) for n = 1..112</a>
%F A222836 Empirical: a(n) = 2*a(n-1) +2*a(n-2) -4*a(n-3) +4*a(n-4) -4*a(n-5) +2*a(n-6) -6*a(n-7) +a(n-10) for n>14
%e A222836 Some solutions for n=4
%e A222836 ..0..1..2..2..3..0....0..1..1..2..0..3....0..1..2..2..1..3....0..1..2..0..3..1
%e A222836 ..0..3..3..0..1..1....0..2..3..3..1..2....0..1..3..3..0..0....2..1..3..0..2..2
%e A222836 ..2..2..1..0..2..3....1..2..0..0..1..2....3..2..0..1..2..2....2..0..3..1..1..3
%e A222836 ..3..0..1..3..2..0....3..3..1..2..3..3....3..2..0..1..3..3....3..0..2..2..0..0
%K A222836 nonn
%O A222836 1,1
%A A222836 _R. H. Hardin_ Mar 06 2013