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A199707 Number of -n..n arrays x(0..4) of 5 elements with zero sum and no two neighbors equal. 1

%I

%S 14,200,892,2734,6504,13324,24394,41344,65788,99858,145596,205612,

%T 282386,379036,498440,644218,819692,1028960,1275766,1564716,1899968,

%U 2286630,2729288,3233528,3804374,4447920,5169588,5975974,6872944,7867572,8966146

%N Number of -n..n arrays x(0..4) of 5 elements with zero sum and no two neighbors equal.

%C Row 5 of A199704.

%H R. H. Hardin, <a href="/A199707/b199707.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=2*a(n-1)-a(n-3)-2*a(n-5)+2*a(n-6)+a(n-8)-2*a(n-10)+a(n-11).

%F Empirical g.f.: 2*x*(7 + 86*x + 246*x^2 + 482*x^3 + 618*x^4 + 618*x^5 + 426*x^6 + 222*x^7 + 47*x^8 + 8*x^9) / ((1 - x)^5*(1 + x)^2*(1 + x^2)*(1 + x + x^2)). - _Colin Barker_, May 16 2018

%e Some solutions for n=5:

%e .-5...-1...-3...-4....4....1...-3...-1....5....0...-4....1....4....0....2....1

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

%e .-3...-4....2....3...-3....1...-4...-1...-1....5....1...-3...-3....4...-5....5

%e ..3....2...-5....1...-4...-5....2....1...-3...-2....2....4....1...-4....4....1

%e ..5....3....5....3....2....0....4...-1....2...-1....4....0...-2...-2...-4...-4

%Y Cf. A199704.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 09 2011

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Last modified August 25 13:50 EDT 2019. Contains 326324 sequences. (Running on oeis4.)