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A199835 Number of -n..n arrays x(0..5) of 6 elements with zero sum and no two neighbors summing to zero 1

%I #7 Aug 01 2014 13:21:36

%S 10,426,3556,15708,49302,124982,273728,538968,978690,1667554,2699004,

%T 4187380,6270030,9109422,12895256,17846576,24213882,32281242,42368404,

%U 54832908,70072198,88525734,110677104,137056136,168241010,204860370

%N Number of -n..n arrays x(0..5) of 6 elements with zero sum and no two neighbors summing to zero

%C Row 4 of A199832

%H R. H. Hardin, <a href="/A199835/b199835.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = n*(2*n+1)*(2*n-1)*(66*n^2-35*n+19)/15.

%F Empirical: G.f.: 2*x*(5+183*x+575*x^2+281*x^3+12*x^4) / (x-1)^6 . - _R. J. Mathar_, Aug 01 2014

%e Some solutions for n=3

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 11 2011

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Last modified April 19 06:44 EDT 2024. Contains 371782 sequences. (Running on oeis4.)