A189543 - OEIS

%I #7 May 16 2023 14:34:49

%S 84,432,4620,56440,683144,8655424,111406336,1456853916,19269747584,

%T 256327259704,3425977826592,45971056435280,618874800769152,

%U 8355263758869800,113080150945285296,1533719330087763556

%N Number of arrangements of n+1 nonzero numbers x(i) in -7..7 with the sum of trunc(x(i)/x(i+1)) equal to zero.

%C Column 7 of A189545.

%H R. H. Hardin, <a href="/A189543/b189543.txt">Table of n, a(n) for n = 1..92</a>

%e Some solutions for n=5

%e .-7....4...-7...-7...-4...-7...-4...-7...-7...-7....4...-4...-7....4...-4...-4

%e .-3....2....2...-2...-2...-6....1....4....4....5....2...-4....4....2...-4....2

%e .-6...-7....6...-5....4...-4....1...-2....7....3....5....7....5...-2....6....7

%e .-5....7....3....1....4....3...-4....7...-3...-3...-1...-4....3....4....4....6

%e ..4...-4....2....6...-4....2...-2....2...-7...-5....6...-5...-4...-4....3....4

%e .-2...-6...-7....3....2...-1...-2...-5...-2...-4....2....7...-5....5...-1...-6

%Y Cf. A189545.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 23 2011