A052817 Cycles of rooted trees t where for each t all subtrees at root are distinct. n is total number of nodes.

0, 1, 2, 3, 6, 10, 22, 43, 97, 211, 481, 1090, 2535, 5870, 13774, 32383, 76607, 181709, 432865, 1033657, 2475869, 5943440, 14300623, 34475031, 83266498, 201441441, 488098768, 1184353854, 2877625762, 7000359245, 17049321176

Offset

0,3

Links

Table of n, a(n) for n=0..30.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 782

Formula

G.f.: Sum_{k>=1} (phi(k)/k) * log( 1/(1-B(x^k)) ) where B(x) is the g.f. for A004111. - Sean A. Irvine, Dec 02 2021

Maple

spec := [S, {C=Prod(B, Z), B=PowerSet(C), S=Cycle(C)}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);

Crossrefs

Cf. A004111.

Sequence in context: A074371 A032202 A125702 * A156803 A002992 A130867

Adjacent sequences: A052814 A052815 A052816 * A052818 A052819 A052820

Keyword

easy,nonn

Author

encyclopedia(AT)pommard.inria.fr, Jan 25 2000

Status

approved