A188229 Number of nondecreasing arrangements of n numbers in -n..n with sum zero and not more than two numbers equal

1, 3, 7, 30, 119, 527, 2395, 11376, 55368, 275735, 1397063, 7185356, 37419881, 196993233, 1046785509, 5608211846, 30264466262, 164375822152, 897938065590, 4930713542112, 27202861579741, 150721902660263, 838367664692809

Offset

1,2

Comments

Column 2 of A188236

Links

R. H. Hardin, Table of n, a(n) for n = 1..31

Example

Some solutions for n=4
.-3...-2...-3...-2...-3...-4...-4...-4...-3...-4...-1...-2...-4...-3...-3...-1
.-2...-2...-3....0...-1...-2...-4....0....0...-3....0...-1....0...-3...-1...-1
..2....0....2....0....2....2....4....0....1....3....0...-1....2....3....0....0
..3....4....4....2....2....4....4....4....2....4....1....4....2....3....4....2

Crossrefs

Sequence in context: A136934 A369083 A201794 * A277739 A098644 A182322

Adjacent sequences: A188226 A188227 A188228 * A188230 A188231 A188232

Keyword

nonn

Author

R. H. Hardin Mar 24 2011

Status

approved