A099949 Number of crossing partitions of n.

1, 5, 20, 84, 388, 1951, 10529, 60478, 367953, 2362503, 15955673, 113015123, 837307541, 6473306155, 52110629576, 435951806195, 3783475965645, 34007779661168, 316120859847935, 3034730002671251, 30048957645720682, 306529788241138211, 3217941347005747296, 34730178825735671711, 384990885899299757336, 4379518943963832643173, 51083106730348426001558

Offset

4,2

Links

Table of n, a(n) for n=4..30.

M. Klazar, Bell numbers, their relatives and algebraic differential equations, J. Combin. Theory, A 102 (2003), 63-87.

Crossrefs

Sequence in context: A056884 A006749 A002213 * A006231 A069007 A126987

Adjacent sequences: A099946 A099947 A099948 * A099950 A099951 A099952

Keyword

nonn,easy,nice

Author

N. J. A. Sloane, Nov 12 2004

Extensions

More terms from Vladeta Jovovic, Jul 11 2007

Status

approved