Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A000525
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A000525 Partially labeled rooted trees with n nodes (4 of which are labeled).
(Formerly M5329 N2317)
+0
8
64, 625, 4016, 21256, 100407, 439646, 1823298, 7258228, 27983518, 105146732, 386812476, 1398023732, 4977320988, 17492710572, 60790051789, 209179971147, 713533304668, 2415061934763, 8117293752058, 27111950991825, 90039381031273 (list; graph; listen)
OFFSET

4,1

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. 134.

LINKS

Index entries for sequences related to rooted trees

Index entries for sequences related to trees

FORMULA

G.f.: A(x) = B(x)^4*(64-79*B(x)+36*B(x)^2-6*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-3)^4* (64-79*B(n-3)+ 36*B(n-3)^2- 6*B(n-3)^3)/ (1-B(n-3))^7, x=0, n+1), x, n): seq (a(n), n=4..24); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Aug 21 2008]

CROSSREFS

Cf. A000081, A000107, A000243, A000269, A000444, A000485, A000524, A000526.

Cf. A042977.

Sequence in context: A100415 A070054 A045789 this_sequence A067476 A138332 A091083

Adjacent sequences: A000522 A000523 A000524 this_sequence A000526 A000527 A000528

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

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 22 20:51 EST 2009. Contains 167312 sequences.


AT&T Labs Research