A273660 Number of forests of labeled rooted trees of height at most 1, with n labels, ten of which are used for root nodes and any root may contain >= 1 labels.

115975, 6188545, 188526162, 4324211606, 83234980829, 1422697691415, 22336690031656, 329296289467288, 4628083121855622, 62687799439000450, 824939949711312292, 10611095747493196956, 134039591449028959694, 1668916223557034160170, 20541239452587941670792

Offset

10,1

Links

Alois P. Heinz, Table of n, a(n) for n = 10..986

Formula

E.g.f.: x^10/10! * Sum_{j=0..10} Stirling2(10,j)*exp(x)^j.

a(n) = C(n,10) * Sum_{j=0..10} Stirling2(10,j) * j^(n-10).

Maple

a:= n-> binomial(n, 10)*add(Stirling2(10, j)*j^(n-10), j=0..10):
seq(a(n), n=10..40);

Crossrefs

Column k=10 of A143396.

Sequence in context: A346830 A346863 A255950 * A254565 A237479 A154065

Adjacent sequences: A273657 A273658 A273659 * A273661 A273662 A273663

Keyword

nonn

Author

Alois P. Heinz, May 27 2016

Status

approved