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 A190074 #7 Jul 22 2025 12:01:02 %S A190074 12,144,922,3481,9904,23400,48491,92478,162599,270267,430274,655974, %T A190074 965098,1390174,1947527,2667906,3590889,4753865,6198717,7979654, %U A190074 10128692,12732119,15867500,19571053,23904927,29021539,34967650,41839570,49768153 %N A190074 Number of arrangements of 5 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 A190074 Row 4 of A190071 %H A190074 R. H. Hardin, <a href="/A190074/b190074.txt">Table of n, a(n) for n = 1..200</a> %e A190074 Some solutions for n=4 %e A190074 .-1....1....4....4....1...-3....1...-2...-2....4...-1....1....4...-4....3...-2 %e A190074 ..2....4...-4....2...-1...-3...-4...-3....4...-3....1....2...-2....3....1...-1 %e A190074 ..1...-4....3...-1....3...-4....4....2....3...-3....3...-3....3...-2....2....2 %e A190074 ..4...-3....1....3....4....2...-4....2...-2....4....3...-3....2...-4...-1...-1 %e A190074 .-3....3...-4....3....2...-3...-3...-3...-2....4...-4....3....1...-2....3...-1 %K A190074 nonn %O A190074 1,1 %A A190074 _R. H. Hardin_ May 04 2011