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%I #4 Mar 06 2013 17:56:36
%S 163,6144,5832,10584,22848,55296,138240,301056,642048,1382400,3022848,
%T 6690816,14816256,32741376,72244224,159258624,351111168,774297600,
%U 1707764736,3766818816,8308300800,18324658176,40416165888,89140107264
%N Number of nX7 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 Column 7 of A222838
%H R. H. Hardin, <a href="/A222837/b222837.txt">Table of n, a(n) for n = 1..64</a>
%F 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 Some solutions for n=4
%e ..0..1..2..2..3..1..2....0..1..1..2..0..0..1....0..1..1..2..3..1..2
%e ..2..3..0..0..3..1..0....3..3..0..2..3..3..1....0..3..3..2..0..0..2
%e ..2..3..1..1..2..2..3....1..2..0..1..1..2..0....1..2..0..1..1..3..3
%e ..1..0..2..3..0..0..3....1..2..3..3..0..2..3....3..2..0..3..2..2..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 06 2013
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