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Number of nX3 0..1 arrays with every element equal to 1, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.
1

%I #4 Jan 22 2018 06:25:51

%S 1,7,15,25,47,113,261,601,1397,3223,7501,17523,40935,95683,223799,

%T 523857,1226779,2873985,6734933,15786173,37008905,86776771,203494869,

%U 477250155,1119367539,2625588427,6158890175,14447602189,33892459607,79509969725

%N Number of nX3 0..1 arrays with every element equal to 1, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.

%C Column 3 of A298582.

%H R. H. Hardin, <a href="/A298577/b298577.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) -a(n-3) -7*a(n-4) +2*a(n-5) -2*a(n-6) +4*a(n-7) -3*a(n-8) +13*a(n-9) +8*a(n-10) -5*a(n-11) -15*a(n-12) +4*a(n-14) for n>15

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A298582.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 22 2018