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 A199701 #10 Jul 22 2025 13:22:42 %S A199701 1,10,82,724,6504,59992,559028,5252900,49700882,472873888,4519281222, %T A199701 43353372676,417214414596,4026070558436,38943205468034, %U A199701 377469980604452,3665456335373858,35651726951195532,347268836196275908 %N A199701 Number of -5..5 arrays x(0..n-1) of n elements with zero sum and no two neighbors equal. %C A199701 Column 5 of A199704 %H A199701 R. H. Hardin, <a href="/A199701/b199701.txt">Table of n, a(n) for n = 1..200</a> %e A199701 Some solutions for n=5 %e A199701 .-1....3...-2...-5....3....4....1....1....5....3....1....2....4...-4....0...-2 %e A199701 ..1...-1....1....3...-1...-1...-5...-2...-1....1...-2...-1....1....4...-3....2 %e A199701 .-1...-4....4...-2....2....1....1....0...-4....2....2...-4...-4...-2....4...-1 %e A199701 ..1...-2....1....4...-1...-3....0....5...-5...-5...-1....5...-3....3....1....4 %e A199701 ..0....4...-4....0...-3...-1....3...-4....5...-1....0...-2....2...-1...-2...-3 %K A199701 nonn %O A199701 1,2 %A A199701 _R. H. Hardin_ Nov 09 2011