A302266 - OEIS

%I #4 Apr 04 2018 12:51:46

%S 2,8,29,105,384,1405,5135,18766,68589,250693,916272,3348929,12240187,

%T 44737350,163513041,597632937,2184322000,7983600501,29179707415,

%U 106650542494,389803024901,1424712848861,5207262571120,19032314831801

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

%C Row 2 of A302265.

%H R. H. Hardin, <a href="/A302266/b302266.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

%Y Cf. A302265.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 04 2018