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Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1

%I #4 Jun 09 2019 08:38:51

%S 3,6,9,25,60,160,396,996,2480,6213,15537,38935,97574,244521,612350,

%T 1533665,3841552,9623474,24106566,60386058,151263372,378906980,

%U 949140173,2377551381,5955661956,14918670478,37370561312,93611479464,234492365157

%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A326165.

%H R. H. Hardin, <a href="/A326160/b326160.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) -5*a(n-2) -13*a(n-3) +38*a(n-4) -31*a(n-5) -41*a(n-6) +136*a(n-7) -125*a(n-8) -80*a(n-9) +370*a(n-10) -296*a(n-11) -270*a(n-12) +562*a(n-13) -178*a(n-14) -302*a(n-15) +321*a(n-16) -43*a(n-17) -63*a(n-18) +71*a(n-19) -103*a(n-20) +26*a(n-21) +54*a(n-22) -41*a(n-23) -a(n-24) +15*a(n-25) -5*a(n-26) -2*a(n-27) +a(n-28) for n>30

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A326165.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 09 2019