A071212 Number of labeled cyclic trees with n nodes such that the root is smaller than all its children.

1, 4, 28, 286, 3848, 64198, 1277400, 29507784, 775826832, 22869156168, 746817076080, 26758697374176, 1043610018593088, 44007103062886416, 1994973101346054144, 96747604119630501120, 4997654990315699224320

Offset

2,2

References

C. Chauve, S. Dulucq and O. Guibert, Enumeration of some labeled trees, research report RR-1226-99, LaBRI, Bordeaux I University, 1999.

Links

Table of n, a(n) for n=2..18.

Maple

n -> sum((n! / (n-k)!) * (-1)^(n-1-k) * stirling1(n-1, k), k=0..n) - sum(((n-2)! / (n-1-k)!) * (-1)^(n-k) * stirling1(n, k), k=0..n-1);

Crossrefs

Cf. A000312.

Sequence in context: A369088 A007559 A138208 * A090353 A360018 A360832

Adjacent sequences: A071209 A071210 A071211 * A071213 A071214 A071215

Keyword

easy,nonn

Author

Cedric Chauve (chauve(AT)lacim.uqam.ca), May 16 2002

Status

approved