A318425 - OEIS

%I #4 Aug 26 2018 11:21:08

%S 1,16,36,147,417,1353,4095,12853,39489,123210,380280,1182026,3659119,

%T 11351061,35179874,109070933,338113844,1048217069,3249453631,

%U 10073853147,31229167798,96814146538,300130174990,930430509302,2884410320136

%N Number of nX3 0..1 arrays with every element unequal to 1, 2, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A318430.

%H R. H. Hardin, <a href="/A318425/b318425.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-2) +11*a(n-3) -14*a(n-4) -32*a(n-5) -29*a(n-6) -51*a(n-7) +33*a(n-8) +116*a(n-9) +18*a(n-10) +70*a(n-11) +92*a(n-12) -22*a(n-13) -12*a(n-16) +4*a(n-17) for n>20

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A318430.

%K nonn

%O 1,2

%A _R. H. Hardin_, Aug 26 2018