A230702 - OEIS

%I #4 Oct 28 2013 08:14:46

%S 8,28,244,800,6576,21076,173428,554040,4558536,14555468,119758148,

%T 382358832,3145930352,10044068932,82639468964,263844008200,

%U 2170826159272,6930820136252,57024624645332,182063126310336,1497958570841456

%N Number of (n+3)X(2+3) 0..2 white square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero

%C Column 2 of A230708

%H R. H. Hardin, <a href="/A230702/b230702.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 31*a(n-2) -126*a(n-4) +42*a(n-6) +79*a(n-8) -a(n-10) +8*a(n-12)

%e Some solutions for n=2

%e ..0..x..0..x..2....0..x..2..x..2....0..x..0..x..0....0..x..2..x..2

%e ..x..1..x..0..x....x..1..x..0..x....x..1..x..1..x....x..1..x..0..x

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 28 2013