login
Number of (n+4)X1 arrays of occupancy after each element moves up to +-4 places but not 0
1

%I #4 Feb 24 2013 16:08:18

%S 121,427,1562,5761,21239,78245,287858,1059674,3901868,14366833,

%T 52894813,194725954,716822517,2638639647,9712504051,35749337667,

%U 131581046318,484294944395,1782459967105,6560310404375,24144873322163,88863279809958

%N Number of (n+4)X1 arrays of occupancy after each element moves up to +-4 places but not 0

%C Column 4 of A222555

%H R. H. Hardin, <a href="/A222551/b222551.txt">Table of n, a(n) for n = 1..117</a>

%F Empirical: a(n) = 9*a(n-1) -28*a(n-2) +35*a(n-3) -15*a(n-4) +12*a(n-5) -96*a(n-6) +274*a(n-7) -265*a(n-8) +24*a(n-9) -7*a(n-10) +29*a(n-11) +3*a(n-12) -a(n-13)

%e Some solutions for n=3

%e ..0....0....2....2....0....4....1....0....0....0....1....1....0....0....0....0

%e ..0....0....0....0....0....1....2....4....2....0....1....1....2....0....2....1

%e ..0....3....3....2....1....0....2....1....2....0....0....0....0....2....2....0

%e ..1....2....0....0....3....1....0....0....0....3....3....3....4....0....0....1

%e ..2....2....1....2....0....0....0....1....1....2....0....2....0....4....3....4

%e ..4....0....0....1....2....0....0....0....0....0....0....0....0....1....0....1

%e ..0....0....1....0....1....1....2....1....2....2....2....0....1....0....0....0

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 24 2013