A237636 - OEIS

%I #4 Feb 10 2014 18:12:54

%S 30656,16448,4132,5976,7756,11984,18344,23968,35732,47936,71426,95872,

%T 140200,191744,286672,383488,560800,766976,1146688,1533952,2243200,

%U 3067904,4586752,6135808,8972800,12271616,18347008,24543232,35891200

%N Number of (n+1)X(7+1) 0..2 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

%C Column 7 of A237637

%H R. H. Hardin, <a href="/A237636/b237636.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-4) for n>15

%e Some solutions for n=5

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 10 2014