|
%I #7 Dec 10 2015 01:54:40
%S 972,2016,4560,13344,33792,86496,240192,608256,1556928,4323456,
%T 10948608,28024704,77822208,197074944,504444672,1400799744,3547348992,
%U 9080004096,25214395392,63852281856,163440073728,453859117056,1149341073408
%N Number of (n+1) X 4 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly two counterclockwise and two clockwise edge increases.
%C Column 3 of A206094.
%H R. H. Hardin, <a href="/A206089/b206089.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 18*a(n-3) for n>6.
%e Some solutions for n=4:
%e ..2..2..0..2....2..2..0..1....0..0..1..2....0..0..1..2....1..2..1..1
%e ..0..2..2..0....2..0..1..1....1..0..0..1....0..1..2..2....0..1..1..0
%e ..1..0..2..2....0..1..1..0....0..1..0..0....1..2..2..1....1..1..0..2
%e ..1..1..0..2....1..1..0..2....0..0..2..2....2..2..0..2....0..0..2..2
%e ..2..1..1..0....1..0..2..2....1..0..2..1....0..0..2..2....2..0..2..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 03 2012
| 