|
|
A188230
|
|
Number of nondecreasing arrangements of n numbers in -(n+1)..(n+1) with sum zero and not more than two numbers equal
|
|
1
|
|
|
1, 4, 12, 52, 221, 1019, 4818, 23522, 117209, 594789, 3062414, 15966168, 84132345, 447457816, 2399177028, 12956403904, 70416558196, 384897011042, 2114694606220, 11672750655842, 64705139473661, 360068911514032, 2010827078176568
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
Some solutions for n=4
.-3...-5...-5...-3...-3...-1...-4...-5...-4...-4...-2...-5...-4...-4...-4...-3
.-2...-5....0...-3....0...-1....1...-1...-2...-4...-2...-3...-1...-3...-3...-1
..1....5....1....2....1....0....1....2....2....3....1....3....2....2....3....2
..4....5....4....4....2....2....2....4....4....5....3....5....3....5....4....2
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|