A228972 - OEIS

%I #8 Sep 13 2013 21:37:48

%S 9,81,729,6387,55887,488037,4259277,37155951,324050745,2825717151,

%T 24637772289,214806377331,1872733313427,16326535353843,

%U 142332941107035,1240830892976931,10817256322467417,94301798866919901,822094581839055501

%N Number of nX2 0..2 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1)X3 0..2 array.

%C Column 2 of A228977.

%H R. H. Hardin, <a href="/A228972/b228972.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 13*a(n-1) -26*a(n-2) -122*a(n-3) +179*a(n-4) +248*a(n-5) -404*a(n-6) +135*a(n-7) +130*a(n-8) -374*a(n-9) +297*a(n-10) -120*a(n-11) +45*a(n-12).

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Sep 10 2013