A189948 1/4 the number of arrangements of n+1 nonzero numbers x(i) in -6..6 with the sum of sign(x(i))*(|x(i)| mod x(i+1)) equal to zero

14, 61, 542, 6733, 77459, 839968, 9133420, 101599137, 1148390301, 13075280021, 149477475730, 1715275336520, 19756078906837, 228289957465939, 2645189908828920, 30720393567321132, 357493766148806039

Offset

1,1

Comments

Column 6 of A189951

Links

R. H. Hardin, Table of n, a(n) for n = 1..133

Example

Some solutions with n=3
.-3...-6...-1...-4...-2...-2...-4....2...-1....1....6...-5....1....2....6...-6
.-2....5....6...-2....3....3....4....2...-5....5...-1...-1...-4...-2...-1....6
..1...-3....1...-1...-5...-5....4...-5....1...-2....3...-1...-3....2...-1...-3
.-3....2...-4...-1...-2....2...-2...-3...-2...-4...-2...-1...-1....2...-1...-1

Crossrefs

Sequence in context: A164540 A140184 A264854 * A252255 A025415 A371420

Adjacent sequences: A189945 A189946 A189947 * A189949 A189950 A189951

Keyword

nonn

Author

R. H. Hardin May 02 2011

Status

approved