%I #4 Nov 25 2014 09:24:51
%S 5,25,83,297,989,3113,9611,29257,88503,266769,802699,2412545,7246311,
%T 21755889,65301163,195969945,588042095,1764390025,5293696363,
%U 15882140601,47648522543,142949767457,428857697715,1286589881041,3859803210479
%N Number of length n+2 0..2 arrays with the sum of second differences multiplied by some arrangement of +1 equal to zero
%C Column 2 of A250561
%H R. H. Hardin, <a href="/A250555/b250555.txt">Table of n, a(n) for n = 1..106</a>
%F Empirical: a(n) = 4*a(n1) +2*a(n2) 17*a(n3) 3*a(n4) +24*a(n5) +16*a(n6) 13*a(n7) 26*a(n8) +2*a(n9) +12*a(n10) for n>15
%e Some solutions for n=6
%e ..2....1....2....0....0....2....0....2....0....2....2....2....1....2....1....0
%e ..1....0....2....2....0....0....2....2....0....2....0....1....0....2....1....0
%e ..2....1....2....1....1....2....2....1....0....0....2....0....1....1....1....2
%e ..1....0....0....0....2....2....0....2....2....2....0....0....0....0....2....2
%e ..1....0....0....0....1....1....0....0....1....1....1....0....0....1....2....0
%e ..1....0....0....0....0....2....0....1....1....2....1....2....1....0....1....2
%e ..2....1....0....1....1....1....2....1....2....2....0....0....1....0....0....2
%e ..1....2....0....1....1....1....0....1....2....0....0....1....0....2....2....2
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 25 2014
