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 A188116 #11 Jul 22 2025 10:59:52 %S A188116 0,3,4,16,42,137,426,1398,4622,15594,53252,184060,642392,2261829, %T A188116 8024726,28664946,103015222,372234190,1351655526,4930080182, %U A188116 18055480464,66371559466,244817099870,905883648170,3361795172242,12509691344838 %N A188116 Number of strictly increasing arrangements of n nonzero numbers in -(n+1)..(n+1) with sum zero. %C A188116 Column 3 of A188122 %H A188116 R. H. Hardin, <a href="/A188116/b188116.txt">Table of n, a(n) for n = 1..30</a> %e A188116 Some solutions for n=6 %e A188116 .-4...-5...-7...-7...-7...-5...-7...-7...-7...-7...-6...-7...-5...-5...-7...-6 %e A188116 .-3...-3...-6...-5...-5...-4...-3...-4...-6...-4...-5...-6...-3...-2...-6...-4 %e A188116 .-2...-2...-1...-2....1...-3....1...-2....1...-2...-4...-2...-2...-1...-1...-2 %e A188116 ..2...-1....3....2....2....3....2....3....3....2....2....3...-1....1....2....1 %e A188116 ..3....5....5....5....4....4....3....4....4....4....6....5....4....3....5....5 %e A188116 ..4....6....6....7....5....5....4....6....5....7....7....7....7....4....7....6 %Y A188116 Equals A188114(n+2) %K A188116 nonn %O A188116 1,2 %A A188116 _R. H. Hardin_ Mar 21 2011