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A187980 Number of nondecreasing arrangements of n numbers x(i) in -(n-1)..(n-1) with the sum of sign(x(i))*2^|x(i)| zero 0
0, 1, 3, 9, 36, 117, 411, 1452, 5040, 17829, 62870, 222458, 789895, 2808018 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 1 of A187988

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

All solutions for n=3

.-1...-2...-1

.-1....1....0

..2....1....0

CROSSREFS

Sequence in context: A125792 A223310 A149020 * A057390 A183495 A185162

Adjacent sequences:  A187977 A187978 A187979 * A187981 A187982 A187983

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 18 2011

STATUS

approved

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Last modified April 19 16:18 EDT 2019. Contains 322282 sequences. (Running on oeis4.)