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A007748 Number of self-converse oriented trees with n nodes. 0
1, 1, 1, 2, 3, 7, 10, 26, 39, 107, 160, 458, 702, 2058, 3177, 9498, 14830, 44947, 70678, 216598, 342860, 1059952, 1686486, 5251806, 8393681, 26297238, 42187148, 132856766, 213828802, 676398395, 1091711076 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

REFERENCES

R. Simion, Trees with 1-factors and oriented trees, Discrete Math., 88 (1991), 93-104.

LINKS

Index entries for sequences related to trees

FORMULA

a(2n)=A000151(n). a(2n-1)=A005750(n). - Christian G. Bower (bowerc(AT)usa.net), Dec 15 1999.

CROSSREFS

Cf. A000238.

Sequence in context: A079380 A062113 A130968 * A126617 A117733 A066236

Adjacent sequences:  A007745 A007746 A007747 * A007749 A007750 A007751

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 16 02:51 EST 2012. Contains 205860 sequences.