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%I #9 Aug 14 2018 21:03:54
%S 3,31,308,3034,29860,293848,2891636,28455036,280009384,2755404412,
%T 27114269752,266815111088,2625565876172,25836603103756,
%U 254242357913972,2501845009992824,24619140986161492,242262050800828048
%N Number of n X 2 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns.
%C Column 2 of A222093.
%H R. H. Hardin, <a href="/A222090/b222090.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 17*a(n-1) - 90*a(n-2) + 217*a(n-3) - 258*a(n-4) + 156*a(n-5) - 44*a(n-6) + 4*a(n-7).
%F Empirical g.f.: x*(3 - 20*x + 51*x^2 - 63*x^3 + 49*x^4 - 18*x^5 + 2*x^6) / (1 - 17*x + 90*x^2 - 217*x^3 + 258*x^4 - 156*x^5 + 44*x^6 - 4*x^7). - _Colin Barker_, Aug 14 2018
%e Some solutions for n=3:
%e ..0..0....0..3....1..2....1..1....1..0....2..2....0..0....2..1....2..0....1..0
%e ..4..0....0..0....1..2....1..2....3..0....1..1....1..2....0..1....2..1....0..2
%e ..1..1....1..2....0..0....1..0....0..2....0..0....2..1....1..1....1..0....1..2
%Y Cf. A222093.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 07 2013
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