

A000393


Number of nnode rooted trees of height 6.
(Formerly M4170 N1736)


2



0, 0, 0, 0, 0, 0, 1, 6, 26, 94, 308, 941, 2744, 7722, 21166, 56809, 149971, 390517, 1005491, 2564164, 6485901, 16289602, 40659669, 100934017, 249343899, 613286048, 1502515487, 3667953650, 8925161513, 21652815724, 52387028291
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,8


REFERENCES

J. Riordan, Enumeration of trees by height and diameter, IBM J. Res. Dev. 4 (1960), 473478.
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

N. J. A. Sloane, Table of n, a(n) for n=1..200
Index entries for sequences related to rooted trees
Index entries for sequences related to trees


FORMULA

A034823A001385. (Christian G. Bower).


MAPLE

For Maple program see link in A000235.


MATHEMATICA

f[n_] := Nest[CoefficientList[Series[Product[1/(1  x^i)^#[[i]], {i, 1, Length[#]}], {x, 0, 40}], x] &, {1}, n]; f[6]f[5] (* Geoffrey Critzer, Aug 01 2013 *)


CROSSREFS

Column h=6 of A034781.
Sequence in context: A224288 A036638 A036645 * A106392 A143132 A055589
Adjacent sequences: A000390 A000391 A000392 * A000394 A000395 A000396


KEYWORD

nonn


AUTHOR

N. J. A. Sloane.


STATUS

approved



