A303422 - OEIS

%I #4 Apr 23 2018 10:55:54

%S 4,32,252,1985,15647,123337,972168,7662841,60400282,476088932,

%T 3752642337,29579189147,233149966025,1837741608616,14485501658565,

%U 114178052735590,899977648952776,7093830637396745,55915203194889879,440736480491065049

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

%C Row 3 of A303421.

%H R. H. Hardin, <a href="/A303422/b303422.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) +4*a(n-2) +21*a(n-3) +18*a(n-4)

%e Some solutions for n=5

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

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

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

%Y Cf. A303421.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 23 2018