A189540 Number of arrangements of n+1 nonzero numbers x(i) in -4..4 with the sum of trunc(x(i)/x(i+1)) equal to zero

24, 72, 544, 3664, 26804, 204544, 1526520, 11544464, 87396896, 665272176, 5096651048, 39149596736, 301739941644, 2331728722640, 18056185672312, 140109131577968, 1089078310071600, 8478661335953200, 66101375005684576

Offset

1,1

Comments

Column 4 of A189545

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Example

Some solutions for n=5
..1...-1....2...-3...-1....2....1...-4...-4...-4....2....3...-3....4...-3....1
..2...-2...-1...-3...-3...-1...-1...-2...-1....3....2...-2...-1....3...-2....1
..2...-1...-3...-1....1...-3...-1....3...-2....2...-4...-3...-3...-4...-2....4
..2....1....3....2....3...-2....1....3....1...-2...-2....4....2...-3...-3...-3
.-1...-4....1....4....1....2....1...-1...-1....4....2....3...-1...-3...-3....3
.-2....4....2...-1...-3....1...-3....3....1....3...-1....4....2....1....1....3

Crossrefs

Sequence in context: A305065 A192833 A292353 * A329077 A339883 A042128

Adjacent sequences: A189537 A189538 A189539 * A189541 A189542 A189543

Keyword

nonn

Author

R. H. Hardin Apr 23 2011

Status

approved