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A007831 Number of edge-labeled series-reduced trees with n nodes. 1
1, 0, 1, 1, 16, 61, 806, 6329, 89272, 1082281, 17596162, 284074165, 5407229972, 107539072733, 2380274168806, 55833426732529, 1418006883852784, 38195636967960913, 1097755724834189834, 33345176998235584301, 1071124330593423824908, 36203857373308709200645 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Table of n, a(n) for n=1..22.

P. J. Cameron, Counting two-graphs related to trees, Elec. J. Combin., Vol. 2, #R4.

Index entries for sequences related to trees

FORMULA

a(n) = A005512(n+1) / (n+1) for n >= 2. - Sean A. Irvine, Feb 03 2018

CROSSREFS

Cf. A005512.

Sequence in context: A317431 A241523 A264632 * A214524 A118254 A066391

Adjacent sequences:  A007828 A007829 A007830 * A007832 A007833 A007834

KEYWORD

nonn

AUTHOR

Peter J. Cameron

STATUS

approved

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Last modified February 16 15:17 EST 2020. Contains 331961 sequences. (Running on oeis4.)