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A179544 Number of Dyck paths of semilength n for which the multiset of ascent lengths and the multiset of descent lengths are the same partition of n. 0
1, 1, 2, 5, 12, 30, 80, 219, 614, 1766, 5206, 15646, 47834, 148602, 468110, 1492841, 4814682, 15686156, 51575438 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..18.

EXAMPLE

For n=4 the paths UUUDDUDD and UUDUUDDD fail the definition because {2,2} != {3,1} so a(4) = 12 rather than Catalan(4)=14.

CROSSREFS

Sequence in context: A101785 A003089 A213263 * A182488 A261788 A112412

Adjacent sequences:  A179541 A179542 A179543 * A179545 A179546 A179547

KEYWORD

nonn,more

AUTHOR

David Scambler, Jan 08 2011

EXTENSIONS

a(15)-a(18) from Alois P. Heinz, May 07 2012

STATUS

approved

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Last modified August 20 20:09 EDT 2017. Contains 290837 sequences.