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%I #9 Aug 04 2018 10:35:03
%S 0,5,53,467,3913,32299,265353,2176758,17847997,146319703,1199485661,
%T 9832876386,80605364957,660764392260,5416629053076,44402915641056,
%U 363993693602517,2983844751876537,24460120087308763,200512266365651825
%N Number of n X 2 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops.
%C Column 2 of A221240.
%H R. H. Hardin, <a href="/A221236/b221236.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 11*a(n-1) - 23*a(n-2) - a(n-3) + 10*a(n-4) - a(n-6).
%F Empirical g.f.: x^2*(5 - 2*x - x^2) / ((1 - 3*x + x^2)*(1 - 8*x - 2*x^2 + 3*x^3 + x^4)). - _Colin Barker_, Aug 04 2018
%e Some solutions for n=3:
%e ..1..0....0..0....1..1....0..2....1..1....0..1....1..1....0..2....0..2....0..1
%e ..2..1....2..1....1..3....1..1....1..2....3..2....2..0....2..2....1..3....0..3
%e ..2..0....2..1....0..0....1..1....1..0....0..0....2..0....0..0....0..0....1..1
%Y Cf. A221240.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jan 06 2013
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