A202044 - OEIS

%I #5 Mar 31 2012 12:36:46

%S 51,1593,19541,359017,6221993,119412837,2229078023,43322352587,

%T 834780981463,16419276700137,322292535850539,6395286541286533,

%U 126942458619056105,2535214795070175713,50692230117983107173

%N Number of zero-sum nX5 -1..1 arrays with every element unequal to at most two horizontal and vertical neighbors

%C Column 5 of A202047

%H R. H. Hardin, <a href="/A202044/b202044.txt">Table of n, a(n) for n = 1..19</a>

%e Some solutions for n=3

%e .-1..0..0..0..1...-1.-1..1.-1.-1....1..1..0..0..1...-1..1.-1.-1.-1

%e ..1..1..1..0..0....1..1..1..0..0...-1.-1.-1..0..0...-1..1..1..1..1

%e .-1.-1..1.-1.-1....1..0..0..0.-1....1..1.-1..0.-1....1..1.-1.-1..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Dec 10 2011