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A228685 Number of 4 X n binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally. 1

%I #10 Sep 12 2018 12:04:02

%S 16,41,313,1152,6737,28977,152048,699833,3508329,16628064,81753697,

%T 392401121,1913315024,9233466953,44861599897,217002245696,

%U 1052716150641,5097234627985,24711403148208,119703506867161,580159930998217

%N Number of 4 X n binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally.

%H R. H. Hardin, <a href="/A228685/b228685.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) + 16*a(n-2) - 7*a(n-3) - 18*a(n-4).

%F Empirical g.f.: x*(1 + x)*(16 - 7*x - 18*x^2) / (1 - 2*x - 16*x^2 + 7*x^3 + 18*x^4). - _Colin Barker_, Sep 12 2018

%e Some solutions for n=4:

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

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

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

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

%Y Row 4 of A228683.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 30 2013

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Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)