A190074 - OEIS

%I #5 Mar 31 2012 12:36:19

%S 12,144,922,3481,9904,23400,48491,92478,162599,270267,430274,655974,

%T 965098,1390174,1947527,2667906,3590889,4753865,6198717,7979654,

%U 10128692,12732119,15867500,19571053,23904927,29021539,34967650,41839570,49768153

%N 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 Row 4 of A190071

%H R. H. Hardin, <a href="/A190074/b190074.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for n=4

%e .-1....1....4....4....1...-3....1...-2...-2....4...-1....1....4...-4....3...-2

%e ..2....4...-4....2...-1...-3...-4...-3....4...-3....1....2...-2....3....1...-1

%e ..1...-4....3...-1....3...-4....4....2....3...-3....3...-3....3...-2....2....2

%e ..4...-3....1....3....4....2...-4....2...-2....4....3...-3....2...-4...-1...-1

%e .-3....3...-4....3....2...-3...-3...-3...-2....4...-4....3....1...-2....3...-1

%K nonn

%O 1,1

%A _R. H. Hardin_ May 04 2011