login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A188255 Number of arrangements of 9 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero 0
140, 16272, 355396, 2880240, 14715004, 55994544, 168083116, 445304272, 1033172284, 2215496776, 4323822892 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A188249

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

Some solutions for n=4

.-4...-2...-3...-4...-3...-3...-4...-3...-4...-3...-3...-3...-2...-2...-4...-4

.-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4

.-2....1....3....1....1....1....1....1....1...-3....4....2...-4...-3...-2....3

.-1....1...-4....2...-1....3...-4...-1...-2....2....1....2...-4...-4....3....4

.-4...-3...-3...-1...-1...-1....4....3...-1...-2....3...-1....3....2...-1...-1

..3....4...-3....3...-2....4....2...-4....1....1...-2...-3...-1...-3...-2....4

.-1....3....1...-2....3...-1....3...-2....3...-4...-1....2....4....4....4....2

..3....2....2....3...-1...-4...-3....1...-2....4....1...-3...-3...-1...-3...-4

.-4...-4...-4....1....1....1...-1....2....4....2....2...-1....3....2...-1....2

CROSSREFS

Sequence in context: A035820 A075915 A159362 * A159366 A189505 A190078

Adjacent sequences:  A188252 A188253 A188254 * A188256 A188257 A188258

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 25 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 16 01:13 EDT 2019. Contains 328038 sequences. (Running on oeis4.)