%I #4 Apr 06 2018 12:22:39

%S 4,2,31,20,154,284,1109,3472,12763,48721,190256,770983,3134572,

%T 12931018,53433431,221779682,921445395,3833216521,15953742306,

%U 66423173327,276603513242,1151978426752,4797997758989,19984422198978,83240190604547

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

%C Row 3 of A302367.

%H R. H. Hardin, <a href="/A302369/b302369.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) +a(n-2) -47*a(n-3) +13*a(n-4) +158*a(n-5) -30*a(n-6) -242*a(n-7) -62*a(n-8) +224*a(n-9) +26*a(n-10) +11*a(n-11) +64*a(n-12) -114*a(n-13) -27*a(n-14) +26*a(n-15) -6*a(n-16) for n>18

%e Some solutions for n=5

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

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

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

%Y Cf. A302367.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 06 2018