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

Author

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

Keywords

• easy
• nonn

References

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

Crossrefs

Cf. A000312.

Programs

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);