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A197607 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,1,1,1 for x=0,1,2,3,4. 2

%I

%S 1,5,14,43,124,352,1025,2977,8619,24982,72411,209844,608174,1762633,

%T 5108427,14805217,42908476,124357153,360411436,1044543248,3027291501,

%U 8773685473,25427864489,73694947188,213582435997,619003863520

%N Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,1,1,1 for x=0,1,2,3,4.

%C Every 0 is next to 0 4's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's.

%C Column 2 of A197613.

%H R. H. Hardin, <a href="/A197607/b197607.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 2*a(n-1) + a(n-2) + 4*a(n-3) + a(n-4) + 2*a(n-5) + 2*a(n-6) - a(n-7) - a(n-8).

%F Empirical g.f.: x*(1 + x)*(1 + 2*x + x^2 + 5*x^3 - 2*x^4 - x^6) / (1 - 2*x - x^2 - 4*x^3 - x^4 - 2*x^5 - 2*x^6 + x^7 + x^8). - _Colin Barker_, Mar 02 2018

%e Some solutions for n=4:

%e ..1..0....0..0....0..0....1..2....0..0....1..2....2..1....0..1....0..0....1..2

%e ..2..1....1..0....0..0....0..1....2..1....3..1....1..3....1..2....2..1....0..1

%e ..0..1....2..0....2..1....2..1....1..0....1..0....0..1....0..0....1..1....1..0

%e ..1..2....1..0....1..0....1..0....0..0....2..1....1..2....0..0....1..2....2..1

%Y Cf. A197613.

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 16 2011

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Last modified May 25 16:14 EDT 2022. Contains 354071 sequences. (Running on oeis4.)