|
%I #5 Mar 31 2012 12:36:27
%S 1,5,25,113,547,2499,11647,54845,256395,1198317,5607683,26243839,
%T 122783657,574447047,2687794239,12575875245,58839924859,275301009225,
%U 1288087194957,6026735743519,28198022800317,131933577537561
%N Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,3,4,1,0 for x=0,1,2,3,4
%C Every 0 is next to 0 2's, every 1 is next to 1 3's, every 2 is next to 2 4's, every 3 is next to 3 1's, every 4 is next to 4 0's
%C Column 4 of A196989
%H R. H. Hardin, <a href="/A196985/b196985.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) +6*a(n-2) +25*a(n-3) +33*a(n-4) +a(n-5) -135*a(n-6) -117*a(n-7) +48*a(n-8) +141*a(n-9) -24*a(n-10) -135*a(n-11) -106*a(n-12) +18*a(n-13) +45*a(n-14) +27*a(n-15) +6*a(n-16) +2*a(n-17)
%e Some solutions for n=5
%e ..0..0..0..0....1..3..1..0....1..0..0..0....1..3..1..1....1..1..3..1
%e ..0..0..0..0....0..1..0..0....3..1..0..1....0..1..1..3....3..1..1..1
%e ..0..4..0..0....0..1..0..0....1..0..1..3....0..0..0..1....1..1..1..3
%e ..0..0..1..0....0..3..1..0....0..0..1..1....0..1..3..1....1..3..0..1
%e ..0..1..3..1....0..1..0..0....0..1..3..1....0..0..1..0....0..1..0..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Oct 08 2011
| 