A205460 - OEIS

%I #5 Mar 31 2012 12:37:06

%S 2120,34792,597288,10306944,177411808,3053150968,52550629576,

%T 904498008200,15568043401040,267954287846248,4611981247042176,

%U 79380591266662712,1366284435462423144,23516241641189712120

%N Number of (n+1)X3 0..3 arrays with the number of clockwise edge increases in every 2X2 subblock differing from each horizontal or vertical neighbor

%C Column 2 of A205466

%H R. H. Hardin, <a href="/A205460/b205460.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 13*a(n-1) +47*a(n-2) +381*a(n-3) +889*a(n-4) +1738*a(n-5) +1450*a(n-6) -1327*a(n-7) -5850*a(n-8) -6842*a(n-9) -201*a(n-10) +5987*a(n-11) +1609*a(n-12) -3010*a(n-13) +750*a(n-14) +1215*a(n-15) -1779*a(n-16) -1448*a(n-17) +771*a(n-18) +670*a(n-19) -118*a(n-20) -168*a(n-21) +44*a(n-22)

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 27 2012