A187997 Number of nondecreasing arrangements of n numbers x(i) in -(n+2)..(n+2) with the sum of sign(x(i))*x(i)^2 zero.

1, 5, 8, 34, 88, 421, 1696, 8373, 40681, 211234, 1111148, 5987390, 32752144, 181900825, 1022304310, 5807285713, 33301251729, 192592146915, 1122301928144, 6585197085192, 38881934489280, 230894913761474, 1378357322150656, 8268192777096128

Offset

1,2

Links

Table of n, a(n) for n=1..24.

Example

All solutions for n=3
.-5....0...-4...-1...-4...-5...-2...-3
..3....0...-3....0....0....0....0....0
..4....0....5....1....4....5....2....3

Crossrefs

Column 4 of A188002.

Sequence in context: A199396 A275003 A032790 * A188065 A204676 A219947

Adjacent sequences: A187994 A187995 A187996 * A187998 A187999 A188000

Keyword

nonn

Author

R. H. Hardin, Mar 18 2011

Extensions

Terms from a(17) on by R. J. Mathar, May 10 2023

Status

approved