A190064 Number of arrangements of n+1 nonzero numbers x(i) in -2..2 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.

2, 12, 40, 144, 550, 1896, 7584, 27328, 105348, 398760, 1538696, 5872800, 22646862, 87492676, 339055650, 1313842904, 5104724558, 19873572892, 77470783406, 302258087616, 1180840902336, 4618922848536, 18083348822516, 70852652846320

Offset: 1

Author

R. H. Hardin May 04 2011

Keywords

• nonn

Comments

Column 2 of A190071

Examples

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

Links

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