A317810 - OEIS

%I #4 Aug 07 2018 21:56:54

%S 1,2,2,4,5,8,9,28,44,60,118,256,409,700,1342,2570,4409,7921,14776,

%T 27269,48326,87891,161611,294704,530298,966374,1764843,3208891,

%U 5812069,10586099,19278834,35040632,63631413,115816700,210701003,383023861

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

%C Column 3 of A317815.

%H R. H. Hardin, <a href="/A317810/b317810.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-2) +2*a(n-3) +2*a(n-4) -8*a(n-5) +5*a(n-6) -8*a(n-7) +9*a(n-8) -4*a(n-9) +7*a(n-10) +2*a(n-11) -4*a(n-12) -2*a(n-13) -4*a(n-14) +2*a(n-15) -a(n-16) +2*a(n-17) for n>19

%e All solutions for n=5

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

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

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

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

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

%Y Cf. A317815.

%K nonn

%O 1,2

%A _R. H. Hardin_, Aug 07 2018