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A000526 Partially labeled trees with n nodes (5 of which are labeled).
(Formerly M5387 N2340)
8
125, 1296, 8716, 47787, 232154, 1040014, 4395772, 17781210, 69498964, 264248924, 982218072, 3582421612, 12857819052, 45515994861, 159205157535, 551049504784, 1889714853263, 6427147635062, 21698583468717 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,1

REFERENCES

J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 138.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=5..23.

Index entries for sequences related to trees

FORMULA

G.f.: A(x) = B(x)^5*(125-204*B(x)+118*B(x)^2-24*B(x)^3)/(1-B(x))^7, where B(x) is g.f. for rooted trees with n nodes, cf. A000081.

MAPLE

b:= proc(n) option remember; if n<=1 then n else add(k*b(k)* s(n-1, k), k=1..n-1)/(n-1) fi end: s:= proc(n, k) option remember; add(b(n+1-j*k), j=1..iquo(n, k)) end: B:= proc(n) option remember; add (b(k)*x^k, k=1..n) end: a:= n-> coeff (series (B(n-4)^5* (125-204*B(n-4) +118*B(n-4)^2 -24*B(n-4)^3)/ (1-B(n-4))^7, x=0, n+1), x, n): seq (a(n), n=5..23); [From Alois P. Heinz, Aug 21 2008]

CROSSREFS

Cf. A000055, A000107, A000243, A000269, A000444, A000485, A000524, A000525.

Sequence in context: A088896 A016851 A204795 * A016971 A030082 A017043

Adjacent sequences:  A000523 A000524 A000525 * A000527 A000528 A000529

KEYWORD

nonn,changed

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vladeta Jovovic, Oct 19 2001

STATUS

approved

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Last modified May 24 07:09 EDT 2013. Contains 225617 sequences.