A208874 - OEIS

%I #5 Mar 31 2012 12:37:25

%S 5,143,6520,307165,14493405,683903931,32271626438,1522813452263,

%T 71857577327143,3390770839381669,160001593732718856,

%U 7550056082308516761,356267369073405009281,16811323900505484274607,793282337427660173475274

%N Number of 3Xn 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors

%C Row 3 of A208872

%H R. H. Hardin, <a href="/A208874/b208874.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 61*a(n-1) -722*a(n-2) +3476*a(n-3) -7851*a(n-4) +8583*a(n-5) -4266*a(n-6) +720*a(n-7) for n>8

%e Some solutions for n=4

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 02 2012