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A317890 Number of nX2 0..1 arrays with every element unequal to 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 3

%I

%S 0,1,1,2,5,16,45,123,340,946,2629,7298,20260,56254,156197,433691,

%T 1204165,3343437,9283266,25775569,71567464,198711505,551734847,

%U 1531926100,4253488018,11810073809,32791403882,91047370756,252798683166

%N Number of nX2 0..1 arrays with every element unequal to 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 2 of A317896.

%H R. H. Hardin, <a href="/A317890/b317890.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +a(n-2) +2*a(n-3) +3*a(n-4) +a(n-5) for n>6

%e All solutions for n=5

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

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

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

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

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

%Y Cf. A317896.

%K nonn

%O 1,4

%A _R. H. Hardin_, Aug 10 2018

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Last modified August 13 14:01 EDT 2022. Contains 356091 sequences. (Running on oeis4.)