This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A199702 #10 Jul 22 2025 13:22:49 %S A199702 1,12,114,1236,13324,147072,1643204,18527516,210316392,2400684208, %T A199702 27527644696,316844861020,3658598730648,42361908912360, %U A199702 491666143730354,5718341649577364,66629811252553344,777637357808739752 %N A199702 Number of -6..6 arrays x(0..n-1) of n elements with zero sum and no two neighbors equal. %C A199702 Column 6 of A199704 %H A199702 R. H. Hardin, <a href="/A199702/b199702.txt">Table of n, a(n) for n = 1..200</a> %e A199702 Some solutions for n=5 %e A199702 .-3....0...-4...-3....0....1...-3....3....4....1....6...-1....6...-4....4...-3 %e A199702 ..0...-1....4....6...-2...-2....3....0....2...-1...-1...-5...-2....2...-6....6 %e A199702 ..2....5....0...-6....2....0....5...-4....3....0....1...-2...-3....0...-1...-3 %e A199702 ..3...-1...-4....3....5....6...-4....4...-6...-3...-2....3....4....3....1....5 %e A199702 .-2...-3....4....0...-5...-5...-1...-3...-3....3...-4....5...-5...-1....2...-5 %K A199702 nonn %O A199702 1,2 %A A199702 _R. H. Hardin_ Nov 09 2011