%I #4 May 20 2018 10:29:29

%S 1,8,11,40,94,291,776,2269,6275,17985,50548,143589,405620,1149709,

%T 3252139,9211083,26070305,73816122,208963020,591618663,1674877081,

%U 4741816884,13424434567,38006135552,107599067346,304624934972

%N Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.

%C Column 3 of A304894.

%H R. H. Hardin, <a href="/A304889/b304889.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +3*a(n-2) -7*a(n-3) -8*a(n-4) -8*a(n-5) +26*a(n-6) -13*a(n-7) -16*a(n-8) +76*a(n-9) -33*a(n-10) -22*a(n-11) +27*a(n-12) -23*a(n-13) +11*a(n-14) +7*a(n-15) -5*a(n-16) +5*a(n-17) -2*a(n-18) -2*a(n-19) for n>20

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A304894.

%K nonn

%O 1,2

%A _R. H. Hardin_, May 20 2018