A205937 - OEIS

A205937

Number of (n+1) X 2 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors.

%I #7 Dec 10 2015 02:07:26

%S 256,1776,12712,91440,656272,4711264,33827496,242859696,1743558448,

%T 12517828752,89871316488,645223555056,4632334222640,33257550378496,

%U 238770342344520,1714234994048944,12307232871040912,88358941969931504

%N Number of (n+1) X 2 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors.

%C Column 1 of A205944.

%H R. H. Hardin, <a href="/A205937/b205937.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 16*a(n-2) + 132*a(n-3) + 626*a(n-4) + 1504*a(n-5) + 2204*a(n-6) + 2140*a(n-7) + 1011*a(n-8) + 96*a(n-9) + 80*a(n-10).

%e Some solutions for n=4:

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 01 2012