A305913 - OEIS

%I #4 Jun 14 2018 07:04:34

%S 3,9,13,27,62,135,312,825,2367,6940,21330,67814,216690,699884,2279373,

%T 7427118,24244543,79292187,259332414,848386032,2776599349,9087224618,

%U 29741257114,97348224464,318637326698,1042951906150,3413821643656

%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.

%C Column 3 of A305918.

%H R. H. Hardin, <a href="/A305913/b305913.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +a(n-2) +7*a(n-3) -19*a(n-4) -21*a(n-5) +18*a(n-6) -23*a(n-7) +17*a(n-8) +55*a(n-9) +83*a(n-10) -23*a(n-11) -120*a(n-12) -20*a(n-13) +78*a(n-14) +9*a(n-15) -22*a(n-16) +2*a(n-18) for n>20

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A305918.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 14 2018