login
Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1

%I #4 Apr 17 2018 13:08:14

%S 4,20,68,308,1320,5220,22652,95220,390580,1662564,6961252,28957492,

%T 122178532,511463444,2138409476,8987766644,37641997156,157656704660,

%U 661559870852,2771791087028,11615849382436,48710299475156

%N Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A303016.

%H R. H. Hardin, <a href="/A303011/b303011.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +4*a(n-2) +30*a(n-3) -88*a(n-4) -52*a(n-5) -84*a(n-6) -200*a(n-7) -80*a(n-8) -112*a(n-9) -96*a(n-10)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A303016.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 17 2018