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A036363 Line-labeled 2-trees with n nodes. 0
1, 30, 2940, 612360, 221371920, 123506903520, 98513415000000, 106466143825641600, 149822417112092524800, 266259578976734741798400, 583256031964344606759091200, 1544112027465820312500000000000, 4860420955731492909364541975040000 (list; graph; refs; listen; history; text; internal format)
OFFSET
3,2
REFERENCES
F. Harary and E. Palmer, Graphical Enumeration, (1973), p. 30, Problem 1.13(c).
LINKS
MAPLE
[ seq((2*n-3)!*(2*n-3)^(n-4)/(2*(n-2)!), n=3..20) ];
CROSSREFS
Sequence in context: A230728 A352652 A108091 * A230591 A352182 A001459
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified February 20 21:52 EST 2024. Contains 370219 sequences. (Running on oeis4.)