A188001 Number of nondecreasing arrangements of n numbers x(i) in -(n+6)..(n+6) with the sum of sign(x(i))*x(i)^2 zero

1, 9, 12, 88, 270, 1587, 7674, 43750, 242128, 1393159, 8045324, 46987016, 275921190, 1631855528, 9700469624, 57950502071, 34778286544, 2096134083792, 12683659236886, 77033023135718, 469480677007150

Offset

1,2

Comments

Column 8 of A188002

Links

Table of n, a(n) for n=1..21.

Example

All solutions for n=3
.-4...-9...-3...-7...-5...-1...-5...-2...-4...-6....0...-8
..0....0....0....0....0....0....3....0...-3....0....0....0
..4....9....3....7....5....1....4....2....5....6....0....8

Crossrefs

Sequence in context: A166643 A038302 A246916 * A273614 A281224 A050236

Adjacent sequences: A187998 A187999 A188000 * A188002 A188003 A188004

Keyword

nonn

Author

R. H. Hardin Mar 18 2011

Extensions

Terms from a(16) on by R. J. Mathar, May 10 2023

Status

approved