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A000526 Partially labeled trees with n nodes (5 of which are labeled).
(Formerly M5387 N2340)
+0
9
125, 1296, 8716, 47787, 232154, 1040014, 4395772, 17781210, 69498964, 264248924, 982218072, 3582421612, 12857819052, 45515994861, 159205157535, 551049504784, 1889714853263, 6427147635062, 21698583468717 (list; graph; listen)
OFFSET

5,1

REFERENCES

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

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

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

LINKS

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 (heinz(AT)hs-heilbronn.de), Aug 21 2008]

CROSSREFS

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

Sequence in context: A016815 A088896 A016851 this_sequence A016971 A030082 A017043

Adjacent sequences: A000523 A000524 A000525 this_sequence A000527 A000528 A000529

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Oct 19 2001

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


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