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A187993 Number of nondecreasing arrangements of n numbers x(i) in -(2n-2)..(2n-2) with the sum of sign(x(i))*x(i)^2 zero. 0
1, 3, 5, 34, 117, 862, 5443, 43750, 354103, 3099873, 27848450, 258912232, 2459308291 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A188002.

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

All solutions for n=3

.-1...-2....0...-3...-4

..0....0....0....0....0

..1....2....0....3....4

CROSSREFS

Cf. A188002.

Sequence in context: A263295 A222484 A222630 * A221158 A068111 A162444

Adjacent sequences:  A187990 A187991 A187992 * A187994 A187995 A187996

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 18 2011

STATUS

approved

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Last modified December 3 04:22 EST 2021. Contains 349445 sequences. (Running on oeis4.)