A186594 - OEIS

%I #5 Mar 31 2012 12:36:05

%S 3306753,104547,407733,2526165,5080629,5654805,5711805,5769381,

%T 5831421,5959701,6475413,9316941,19268469,36584472,55233771,81033246,

%U 128348841,198142701,273483585,378799581,578518521,897620265,1289310978,1848325452

%N Number of (n+3)X7 0..3 arrays with every 4X4 subblock commuting with each horizontal and vertical neighbor 4X4 subblock

%C Column 4 of A186599

%H R. H. Hardin, <a href="/A186594/b186594.txt">Table of n, a(n) for n = 1..65</a>

%F Empirical: a(n)=2*a(n-1)-a(n-2)+3*a(n-4)-6*a(n-5)+3*a(n-6)+3*a(n-8)-3*a(n-9) for n>14

%e Some solutions for 5X7

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 24 2011