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 A199527 #7 Jul 22 2025 13:19:54 %S A199527 1,10,90,860,8470,84852,860854,8815392,90927530,943302430,9832131238, %T A199527 102882332054,1080105471952,11371474312404,120012768975248, %U A199527 1269300095287288,13449845528174042,142756162602411602 %N A199527 Number of -5..5 arrays x(0..n-1) of n elements with zero sum and no two consecutive zero elements. %C A199527 Column 5 of A199530 %H A199527 R. H. Hardin, <a href="/A199527/b199527.txt">Table of n, a(n) for n = 1..200</a> %e A199527 Some solutions for n=5 %e A199527 ..1...-2...-3....4....5...-2...-2...-1...-2...-4...-3...-4....4....1...-1...-2 %e A199527 ..1....0....4...-4...-5....1...-5....4....1....5....3...-5...-3...-1....1...-4 %e A199527 .-4...-2....2....2....0....3....3...-3...-4....2....2...-1....1....5...-2....4 %e A199527 .-1....4....0...-4...-3....2....3...-4....1...-3....2....5...-5...-5...-3....0 %e A199527 ..3....0...-3....2....3...-4....1....4....4....0...-4....5....3....0....5....2 %K A199527 nonn %O A199527 1,2 %A A199527 _R. H. Hardin_ Nov 07 2011