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A273658
Number of forests of labeled rooted trees of height at most 1, with n labels, eight of which are used for root nodes and any root may contain >= 1 labels.
2
4140, 153063, 3315645, 55239525, 786082275, 10081916559, 120278261103, 1361959159275, 14838761544750, 157056039953670, 1626124163724918, 16555067600440590, 166368479811851850, 1655233308679110930, 16341232769733507570, 160366537782578273850
OFFSET
8,1
LINKS
FORMULA
E.g.f.: x^8/8! * Sum_{j=0..8} Stirling2(8,j)*exp(x)^j.
a(n) = C(n,8) * Sum_{j=0..8} Stirling2(8,j) * j^(n-8).
MAPLE
a:= n-> binomial(n, 8)*add(Stirling2(8, j)*j^(n-8), j=0..8):
seq(a(n), n=8..40);
CROSSREFS
Column k=8 of A143396.
Sequence in context: A320559 A294058 A255948 * A107541 A254230 A106537
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 27 2016
STATUS
approved