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A228678 Number of nX3 binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally. 1

%I

%S 5,19,77,313,1277,5215,21305,87049,355685,1453363,5938613,24265921,

%T 99153677,405154783,1655515121,6764650225,27641241413,112945711027,

%U 461510880221,1885793543785,7705597945181,31486076453887,128656207802537

%N Number of nX3 binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally.

%C Column 3 of A228683

%H R. H. Hardin, <a href="/A228678/b228678.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) -3*a(n-2) -3*a(n-3).

%F Empirical: G.f. -x*(-5+6*x+3*x^2) / ( 1-5*x+3*x^2+3*x^3 ). - _R. J. Mathar_, Aug 31 2013

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Aug 30 2013

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Last modified November 28 17:54 EST 2021. Contains 349415 sequences. (Running on oeis4.)