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A000395
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6th power of rooted tree enumerator; number of linear forests of 6 rooted trees.
(Formerly M4175 N1739)
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4
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1, 6, 27, 104, 369, 1236, 3989, 12522, 38535, 116808, 350064, 1039896, 3068145, 9004182, 26314773, 76652582, 222705603, 645731148, 1869303857, 5404655358, 15611296146, 45060069406, 129989169909, 374843799786, 1080624405287
(list; graph; refs; listen; history; internal format)
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OFFSET
| 6,2
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REFERENCES
| J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 150.
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).
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LINKS
| Index entries for sequences related to rooted trees
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FORMULA
| G.f.: B(x)^6 where B(x) is g.f. of A000081.
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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-5)^6, x=0, n+1), x, n): seq (a(n), n=6..30); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Aug 21 2008]
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CROSSREFS
| Cf. A000081, A000106, A000242, A000300, A000343.
Sequence in context: A124641 A169793 A054457 * A005325 A099623 A119852
Adjacent sequences: A000392 A000393 A000394 * A000396 A000397 A000398
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from Christian G. Bower (bowerc(AT)usa.net), Nov 15 1999.
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