cp's OEIS Frontend

A190078 Number of arrangements of 9 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.

%I A190078 #7 Jul 22 2025 12:01:31
%S A190078 140,27328,910716,10802667,73725405,353856100,1333341624,4232955454,
%T A190078 11720735320,29213945353,67119317038,143366487211,287901954546,
%U A190078 552087286271,1012169804786,1781377206624,3036183971866,5024176668242
%N A190078 Number of arrangements of 9 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 A190078 Row 8 of A190071
%H A190078 R. H. Hardin, <a href="/A190078/b190078.txt">Table of n, a(n) for n = 1..58</a>
%e A190078 Some solutions for n=4
%e A190078 .-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4
%e A190078 .-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4
%e A190078 ..1....1....1...-1...-4...-3...-3...-1...-4...-3...-3...-3....1....1...-1...-4
%e A190078 ..2....1....1...-4...-2...-4....1....2...-4....1....2....2...-2...-2....3...-4
%e A190078 ..4....3....1....4...-1...-3....4...-1...-2...-3...-1....3...-1....2....2....3
%e A190078 ..2....2....3...-2....2....1....2....3....1....2....3....3...-1....3....4...-4
%e A190078 ..1....3...-4....1....4....3...-1....2....4....3...-4...-3...-1....1...-3....3
%e A190078 .-4....3...-2....3...-1...-2...-2...-2....4....3...-4...-4...-3...-3....2....2
%e A190078 ..4...-4....4...-2....2....1....4....3...-1....2...-4....2....2...-3...-1...-4
%K A190078 nonn
%O A190078 1,1
%A A190078 _R. H. Hardin_ May 04 2011