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 A188357 #6 Jul 22 2025 11:09:56 %S A188357 33,561,2161,34625,283893,4409889,55520361,870473329,12869671489, %T A188357 204942934341,3212586862645 %N A188357 Number of arrangements of n+1 numbers x(i) in -8..8 with the sum of x(i)*x(i+1) equal to zero. %C A188357 Column 8 of A188358 %e A188357 Some solutions for n=4 %e A188357 .-7....6...-2...-3....4...-7...-5....0....0....0...-4...-7....8....1...-5....3 %e A188357 .-1....5....0....8....3....0....0...-6....0...-4...-2...-7...-6...-8....0....3 %e A188357 ..7...-6...-7....3....0...-3...-6...-4...-3....3....4....5....0....1...-7...-5 %e A188357 .-2....4...-5...-7....4....0....4....3...-7...-4....0...-7....6...-8....5...-3 %e A188357 .-7....6....7...-3...-3...-2....6...-4....3...-6...-3...-3....8...-3....7....3 %K A188357 nonn %O A188357 1,1 %A A188357 _R. H. Hardin_ Mar 28 2011