A203367 - OEIS

%I #5 Mar 31 2012 12:36:56

%S 5,110,1570,25087,386353,6026844,93584344,1455532600,22625213338,

%T 351763016010,5468615210324,85018833730862,1321749696997658,

%U 20548711257400038,319462221618691775,4966547386437381855

%N Number of nX4 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by both a 1 and a 0

%C Column 4 of A203371

%H R. H. Hardin, <a href="/A203367/b203367.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) +120*a(n-2) +573*a(n-3) +1592*a(n-4) +1984*a(n-5) -149*a(n-6) -4874*a(n-7) -6407*a(n-8) +5949*a(n-9) +17221*a(n-10) -31639*a(n-11) +19681*a(n-12) -10104*a(n-13) +3649*a(n-14) +2588*a(n-15) -124*a(n-16) -408*a(n-17) +112*a(n-18) -32*a(n-19)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Dec 31 2011