A300925 - OEIS

%I #4 Mar 15 2018 18:57:29

%S 1,11,75,508,3447,23404,158855,1078231,7318522,49674630,337167639,

%T 2288532749,15533466237,105433742828,715633842274,4857380402810,

%U 32969576037134,223781720583309,1518923337407277,10309725472244584

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

%C Column 3 of A300930.

%H R. H. Hardin, <a href="/A300925/b300925.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) +6*a(n-2) -3*a(n-3) -9*a(n-4) -6*a(n-5) +3*a(n-6) +6*a(n-7) +2*a(n-8) for n>10

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A300930.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 15 2018