A240651 - OEIS

%I #4 Apr 09 2014 19:23:33

%S 1,2,9,17,43,136,402,1180,3518,10525,31454,94059,281484,842574,

%T 2522415,7552239,22613578,67714627,202772197,607215863,1818375168,

%U 5445371326,16306993036,48833947510,146241553581,437945846008,1311506541151

%N Number of nX3 0..1 arrays with no element equal to exactly one horizontal or vertical neighbor, with new values 0..1 introduced in row major order

%C Column 3 of A240656

%H R. H. Hardin, <a href="/A240651/b240651.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +a(n-2) +2*a(n-3) -11*a(n-4) -12*a(n-5) -9*a(n-6) +15*a(n-7) +23*a(n-8) +20*a(n-9) -6*a(n-10) -15*a(n-11) -12*a(n-12) -2*a(n-13) +3*a(n-14) +a(n-15)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_, Apr 09 2014