A300641 - OEIS

%I #4 Mar 10 2018 10:36:56

%S 0,2,2,10,30,104,340,1144,3795,12683,42227,140876,469517,1565586,

%T 5219130,17400850,58012053,193409644,644810491,2149754855,7167115016,

%U 23894640479,79662932803,265590322328,885458314722,2952052210282,9841922224851

%N Number of nX3 0..1 arrays with every element equal to 2, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A300646.

%H R. H. Hardin, <a href="/A300641/b300641.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A300646.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 10 2018