%I #6 Jul 23 2025 13:54:39

%S 256,9205,119317,866944,4373134,16987236,54817908,153203700,382427902,

%T 870816931,1838833115,3646368028,6856114327,12312181791,21251285131,

%U 35433012016,57295925135,90169126459,138505569304,208154690963

%N Number of length 7+2 0..n arrays with the sum of medians of adjacent triples multiplied by some arrangement of +-1 equal to zero.

%C Row 7 of A253129

%H R. H. Hardin, <a href="/A253135/b253135.txt">Table of n, a(n) for n = 1..22</a>

%e Some solutions for n=3

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

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

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

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 27 2014