id:A030983 - OEIS Search Results

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Number of rooted noncrossing trees with n nodes such that root has degree 1 and the child of the root has degree at least 2.

+0
2

0, 3, 16, 83, 442, 2420, 13566, 77539, 450340, 2650635, 15777450, 94815732, 574518536, 3506232184, 21533144486, 132980242755, 825304177544, 5144743785545, 32199189658020, 202252227085755, 1274578959894450 (list; graph; listen)

	OFFSET	`3,2`
	REFERENCES	`M. Noy, Enumeration of noncrossing trees on a circle, Discr. Math. 180 (1998), 301-313.`
	LINKS	`Index entries for sequences related to rooted trees`
	FORMULA	`(19n-31)binomial(3n-8, n-4)/(n-1)/(2n-3); G.f.: (1-2z)2sin(arcsin(sqrt(27z)/2)/3)/sqrt(3*z).`
	CROSSREFS	`Row 1 of A102892.` `Sequence in context: A164100 A041707 A037584 this_sequence A069429 A026131 A026160` `Adjacent sequences: A030980 A030981 A030982 this_sequence A030984 A030985 A030986`
	KEYWORD	`nonn`
	AUTHOR	`Emeric Deutsch (deutsch(AT)duke.poly.edu)`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

AT&T Labs Research