A187998 Number of nondecreasing arrangements of n numbers x(i) in -(n+3)..(n+3) with the sum of sign(x(i))*x(i)^2 zero.

1, 6, 9, 46, 117, 636, 2596, 13343, 66452, 354806, 1898800, 10452050, 58080269, 327389928, 1863061322, 10707246833, 62028855007, 362078074528, 2127680924575, 12580327500008, 74800656700824, 447053889525102, 2684568476124840, 16191874238303244

Offset

1,2

Comments

Column 5 of A188002.

Links

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

Example

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

Crossrefs

Cf. A188002.

Sequence in context: A154139 A330983 A299914 * A177181 A126110 A340819

Adjacent sequences: A187995 A187996 A187997 * A187999 A188000 A188001

Keyword

nonn

Author

R. H. Hardin, Mar 18 2011

Extensions

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

Status

approved