A318063 - OEIS

%I #4 Aug 15 2018 13:09:50

%S 1,18,98,649,4003,25106,156846,980960,6133497,38352691,239814461,

%T 1499536299,9376441731,58629916469,366606748842,2292353789490,

%U 14333849236061,89628064900328,560434945455139,3504341284919904

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

%C Column 3 of A318068.

%H R. H. Hardin, <a href="/A318063/b318063.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A318068.

%K nonn

%O 1,2

%A _R. H. Hardin_, Aug 15 2018