A205928 - OEIS

%I #5 Mar 31 2012 12:37:07

%S 256,3036,32208,319784,3048544,28259556,256692580,2295975140,

%T 20290062176,177581881904,1541976728696,13301510850956,

%U 114108632607548,974287139001676,8285017042480392,70205670884081960,593085254039113280

%N Number of (n+1)X2 0..3 arrays with the number of clockwise edge increases in 2X2 subblocks nondecreasing rightwards and downwards

%C Column 1 of A205935

%H R. H. Hardin, <a href="/A205928/b205928.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 16*a(n-1) -63*a(n-2) -27*a(n-3) +182*a(n-4) -217*a(n-5) +114*a(n-6) -4*a(n-7) -4*a(n-8) +4*a(n-9)

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 01 2012