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A304421 Number of nX2 0..1 arrays with every element unequal to 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero. 8

%I #4 May 12 2018 09:34:44

%S 1,7,25,98,383,1493,5824,22717,88609,345626,1348139,5258513,20511208,

%T 80005441,312066973,1217239658,4747930775,18519645245,72237207376,

%U 281766419413,1099050170857,4286924185562,16721455908083,65223240622649

%N Number of nX2 0..1 arrays with every element unequal to 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

%C Column 2 of A304427.

%H R. H. Hardin, <a href="/A304421/b304421.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +3*a(n-2) +2*a(n-3)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A304427.

%K nonn

%O 1,2

%A _R. H. Hardin_, May 12 2018

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Last modified April 23 13:11 EDT 2024. Contains 371913 sequences. (Running on oeis4.)