A316948 - OEIS

%I #4 Jul 17 2018 12:21:16

%S 1,25,160,1240,9417,71505,543155,4125662,31337363,238029974,

%T 1808010056,13733145621,104313185951,792334186609,6018351922536,

%U 45713741090407,347228967561412,2637455457327040,20033384133349773,152168059831839593

%N Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

%C Column 3 of A316953.

%H R. H. Hardin, <a href="/A316948/b316948.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A316953.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jul 17 2018