A318345 - OEIS

%I #4 Aug 24 2018 11:09:16

%S 3,4,6,13,21,41,71,130,237,439,802,1483,2734,5067,9351,17309,32017,

%T 59290,109700,203097,375959,696116,1288668,2385953,4417419,8178970,

%U 15142943,28037280,51910866,96113811,177954611,329485125,610044725,1129506327

%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A318350.

%H R. H. Hardin, <a href="/A318345/b318345.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +a(n-3) +6*a(n-4) -2*a(n-5) -2*a(n-7) -11*a(n-8) -3*a(n-9) -3*a(n-11) +6*a(n-12) +4*a(n-13) +4*a(n-15) -a(n-16) -a(n-17) -a(n-19) for n>25

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A318350.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 24 2018