|
|
A169584
|
|
The number of 2-noncrossing permutations of n elements.
|
|
0
|
|
|
|
OFFSET
|
3,2
|
|
COMMENTS
|
2nd column of table on p.4 of Burrill, Mishna, and Post. Table 2. Column 1 is the Catalan numbers A000108. The number of permutations of S_n with crossing number k. A crossing number of 1 is equivalent to non-crossing.
|
|
LINKS
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|