A208171 - OEIS

%I #5 Mar 31 2012 12:37:22

%S 15,2277,473928,99752346,21002874867,4422202024212,931104734002155,

%T 196046229442844736,41277981610623482478,8691173355900504027213,

%U 1829946411015625966726620,385299398603702723040648261

%N Number of nX4 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 neighbors

%C Column 4 of A208175

%H R. H. Hardin, <a href="/A208171/b208171.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 226*a(n-1) -3345*a(n-2) +19752*a(n-3) -60897*a(n-4) +108504*a(n-5) -114399*a(n-6) +68040*a(n-7) -18225*a(n-8) for n>9

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 24 2012