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%I #8 May 01 2018 14:29:12
%S 2,14,73,400,2177,11854,64554,351521,1914208,10423761,56762346,
%T 309097942,1683185225,9165743600,49911830577,271793641686,
%U 1480045568402,8059551617921,43888089440192,238991507967969,1301422358761490
%N Number of n X 2 array permutations with each element moving zero or one space diagonally, horizontally or vertically.
%C Column 2 of A189312.
%H R. H. Hardin, <a href="/A189305/b189305.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 4*a(n-1) +8*a(n-2) -4*a(n-4) +a(n-5).
%F Empirical g.f.: x*(2 + 2*x - x^2)*(1 + 2*x - x^2) / (1 - 4*x - 8*x^2 + 4*x^4 - x^5). - _Colin Barker_, May 01 2018
%e Some solutions for 3 X 2:
%e ..3..1....0..3....0..1....1..3....0..1....0..1....0..1....3..1....1..0....0..1
%e ..2..0....2..1....2..3....0..2....4..3....5..2....4..3....4..0....3..5....3..2
%e ..4..5....4..5....5..4....5..4....2..5....4..3....5..2....2..5....2..4....4..5
%Y Cf. A189312.
%K nonn
%O 1,1
%A _R. H. Hardin_, Apr 19 2011
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