A210298 - OEIS

%I #5 Mar 31 2012 12:37:32

%S 61973516,482519042626,3744799069935140,29075895528477825602,

%T 225741948376039857049980,1752648993312488853687634462,

%U 13607462253433812638431489199962,105647542211301539024933439827978282

%N Half the number of (n+1)X7 0..3 arrays with every 2X2 subblock having at most one duplicate clockwise edge difference

%C Column 6 of A210300

%H R. H. Hardin, <a href="/A210298/b210298.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 19 2012