login
Number of nX3 0..1 arrays with every element equal to 0, 1 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1

%I #4 Apr 02 2018 14:45:57

%S 3,9,7,17,31,57,111,265,527,1065,2431,4953,10095,22537,46527,95417,

%T 209679,436585,900191,1955353,4093999,8480457,18265087,38377337,

%U 79802575,170819881,359693471,750304217,1598909295,3371088777,7049660735

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

%C Column 3 of A302163.

%H R. H. Hardin, <a href="/A302158/b302158.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A302163.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 02 2018