cp's OEIS Frontend

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

%I A199835 #9 Jul 22 2025 13:24:45
%S A199835 10,426,3556,15708,49302,124982,273728,538968,978690,1667554,2699004,
%T A199835 4187380,6270030,9109422,12895256,17846576,24213882,32281242,42368404,
%U A199835 54832908,70072198,88525734,110677104,137056136,168241010,204860370
%N A199835 Number of -n..n arrays x(0..5) of 6 elements with zero sum and no two neighbors summing to zero.
%C A199835 Row 4 of A199832
%H A199835 R. H. Hardin, <a href="/A199835/b199835.txt">Table of n, a(n) for n = 1..200</a>
%F A199835 Empirical: a(n) = n*(2*n+1)*(2*n-1)*(66*n^2-35*n+19)/15.
%F A199835 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 A199835 Some solutions for n=3
%e A199835 ..0....2....3....2...-1...-3....0...-1....2...-1....1....0....0...-1....0...-2
%e A199835 .-1...-1....0....1...-1....2....2...-3....2....0....3....2...-1....3....3...-2
%e A199835 ..2...-1....1...-3....3....3....0....1...-3....2...-2....1....2...-2...-1...-1
%e A199835 ..1...-2...-3...-3...-2....1...-1....0....2....2....0...-2...-3....1....0....3
%e A199835 .-2....0...-2....2....0....0...-1....2...-1....0...-1...-2...-1...-2...-3....0
%e A199835 ..0....2....1....1....1...-3....0....1...-2...-3...-1....1....3....1....1....2
%K A199835 nonn
%O A199835 1,1
%A A199835 _R. H. Hardin_, Nov 11 2011