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 A190063 #8 Jul 22 2025 11:59:50 %S A190063 0,12,166,3481,88509,2783714,101530262,4232955454,198636188057, %T A190063 10408538943146,603033909983829,38103929980500423,2608648993698684772, %U A190063 193359775333060165517,15364574547397697984616,1301880431718317296701496 %N A190063 Number of arrangements of n+1 nonzero numbers x(i) in -n..n with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero. %C A190063 Diagonal of A190071 %H A190063 R. H. Hardin, <a href="/A190063/b190063.txt">Table of n, a(n) for n = 1..21</a> %e A190063 Some solutions for n=4 %e A190063 ..4...-1...-2....1...-1...-4....4...-3...-2...-4...-3...-3....4...-1....2...-2 %e A190063 ..4...-2...-1....1....2...-4....1...-2...-3....2....1....4....2....1....2...-1 %e A190063 .-2....1...-2....3...-4...-2...-3...-1...-4....2...-4...-2...-2...-1....2...-3 %e A190063 .-1....3....2...-4....4....1....2....3....2...-2...-2...-1....2...-2....4....2 %e A190063 ..1....2...-1....4....2...-1...-1...-1....3...-1...-2...-2...-4...-2...-2...-2 %K A190063 nonn %O A190063 1,2 %A A190063 _R. H. Hardin_ May 04 2011