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%I #9 Oct 16 2018 05:41:56
%S 88,454,2056,10076,46804,226072,1060636,5086576,23991808,114597900,
%T 542168944,2583725396,12245147680,58277217168,276473917972,
%U 1314790543248,6241143226396,29667097057792,140873066386336,669466007785964
%N Number of (n+1) X (1+1) 0..4 arrays with 2 X 2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions but not both.
%H R. H. Hardin, <a href="/A234770/b234770.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) + 21*a(n-2) - a(n-3) - 67*a(n-4) - 10*a(n-5) + 46*a(n-6).
%F Empirical g.f.: 2*x*(44 + 183*x - 123*x^2 - 713*x^3 - 49*x^4 + 513*x^5) / (1 - x - 21*x^2 + x^3 + 67*x^4 + 10*x^5 - 46*x^6). - _Colin Barker_, Oct 16 2018
%e Some solutions for n=5:
%e ..1..3....1..2....1..1....1..3....2..0....4..4....4..4....2..2....3..2....0..2
%e ..2..2....1..0....2..3....2..3....2..1....2..3....3..2....4..3....3..4....0..1
%e ..0..1....2..3....2..1....1..0....2..3....2..4....1..1....1..2....2..1....2..2
%e ..2..1....1..0....0..0....1..2....4..3....2..3....2..0....1..3....0..1....1..3
%e ..3..4....2..2....2..1....0..0....1..2....2..1....1..1....1..2....0..2....2..3
%e ..2..2....1..0....3..0....1..2....3..3....3..4....2..0....0..2....1..2....4..4
%Y Column 1 of A234777.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 30 2013
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