A205950 - OEIS

%I #7 Dec 10 2015 02:02:39

%S 17920,310912,5550256,101702648,1912957100,36783376600,718097911212,

%T 14168783055608,281683319581364,5628530205351848,112878301213615480,

%U 2269166138679395320,45695383178079335324,921207719717378895736

%N Number of (n+1) X 4 0..3 arrays with no 2 X 2 subblock having the same number of clockwise edge increases as its horizontal neighbors or the same number of counterclockwise edge increases as its vertical neighbors.

%C Column 3 of A205954.

%H R. H. Hardin, <a href="/A205950/b205950.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=4:

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 02 2012