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%I #7 Aug 16 2018 08:59:28
%S 2,7,34,370,5314,82690,1313794,20983810,335593474,5368905730,
%T 85900132354,1374392680450,21990245138434,351843771219970,
%U 5629499735539714,90071993352716290,1441151883979784194,23058430105021841410
%N Number of n X 2 0..5 arrays with no element equal to another at a city block distance of exactly two, and new values 0..5 introduced in row major order.
%C Column 2 of A222871.
%H R. H. Hardin, <a href="/A222868/b222868.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 21*a(n-1) - 84*a(n-2) + 64*a(n-3) for n>5.
%F Empirical g.f.: x*(2 - 35*x + 55*x^2 + 116*x^3 - 48*x^4) / ((1 - x)*(1 - 4*x)*(1 - 16*x)). - _Colin Barker_, Aug 16 2018
%e Some solutions for n=3:
%e ..0..0....0..1....0..0....0..0....0..1....0..1....0..1....0..1....0..1....0..1
%e ..1..2....2..2....1..2....1..2....2..3....0..2....0..2....2..1....2..3....2..3
%e ..1..3....1..3....3..4....1..2....1..0....3..4....3..3....3..3....4..5....4..4
%Y Cf. A222871.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 07 2013
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