The On-Line Encyclopedia of Integer Sequences (OEIS)

A034799 revision #9

A034799

Triangle of number of labeled trees by number of nodes and number of labels.

1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 2, 4, 9, 16, 16, 3, 9, 26, 67, 125, 125, 6, 20, 75, 251, 680, 1296, 1296, 11, 48, 214, 888, 3135, 8716, 16807, 16807, 23, 115, 612, 3023, 13155, 47787, 134960, 262144, 262144, 47, 286, 1747, 10038, 51873, 232154, 858578, 2450309, 4782969, 4782969

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

0,8

REFERENCES

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

LINKS

Table of n, a(n) for n=0..54.

Index entries for sequences related to trees

FORMULA

Reference gives generating function.

E.g.f.: r(x,y) - (1/2)*r(x,y)^2 + (1/2)*r(x^2) where r(x,y) is the e.g.f. for A008295 and r(x) is the o.g.f. for A000081. - Sean A. Irvine, Sep 04 2020

CROSSREFS

Cf. A000081, A008295, A034800.

Sequence in context: A343326 A073078 A360296 * A008985 A326699 A138652

Adjacent sequences: A034796 A034797 A034798 * A034800 A034801 A034802

KEYWORD

nonn,tabl

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Sean A. Irvine, Sep 04 2020

STATUS

proposed