|
%I #5 Mar 31 2012 12:36:30
%S 1,9,22,53,162,526,1605,5011,15073,46562,143487,440836,1353988,
%T 4162099,12795741,39330623,120882310,371559669,1142099870,3510484802,
%U 10790188695,33166049781,101943428843,313345715556,963137000727,2960415365620
%N Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,3,1,1,0 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 1's, every 3 is next to 3 1's, every 4 is next to 4 0's
%C Column 3 of A197503
%H R. H. Hardin, <a href="/A197498/b197498.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = a(n-1) +2*a(n-2) +7*a(n-3) +15*a(n-4) +15*a(n-5) +6*a(n-6) -9*a(n-7) -14*a(n-8) -46*a(n-9) -63*a(n-10) +3*a(n-11) +a(n-12) +39*a(n-13) -16*a(n-14) +39*a(n-15) +27*a(n-16) +32*a(n-17) -3*a(n-18) -11*a(n-19) -14*a(n-20) -8*a(n-21)
%e Some solutions for n=4
%e ..0..0..1....0..0..1....2..1..2....0..1..2....0..0..0....0..0..0....1..3..1
%e ..0..1..3....0..1..3....1..3..1....1..3..1....0..0..0....0..1..0....2..1..2
%e ..0..1..1....0..0..1....0..0..0....1..3..1....1..3..1....0..3..1....2..1..2
%e ..1..3..1....0..0..0....0..0..0....0..1..2....0..1..0....0..1..2....1..3..1
%K nonn
%O 1,2
%A _R. H. Hardin_ Oct 15 2011
|
