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A188252 Number of arrangements of 6 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero 0
0, 300, 1632, 7092, 16484, 43440, 75080, 142532, 232432, 380244, 525668, 841504, 1099064, 1531092, 2070976, 2785252, 3396316, 4539424, 5414024, 6981628, 8554708, 10387240, 11982424, 15101088, 17498972 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 4 of A188249

LINKS

Table of n, a(n) for n=1..25.

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Sequence in context: A253650 A054026 A237773 * A128391 A234412 A234406

Adjacent sequences:  A188249 A188250 A188251 * A188253 A188254 A188255

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 25 2011

STATUS

approved

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Last modified September 16 06:38 EDT 2019. Contains 327090 sequences. (Running on oeis4.)