A036661 - OEIS

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A036661

Number of n-node rooted labeled trees with deg <=4 at root and out-degree <=2 elsewhere.

1, 1, 2, 4, 8, 15, 32, 66, 142, 306, 672, 1483, 3316, 7446, 16859, 38353, 87735, 201510, 464801, 1075744, 2498053, 5817576, 13585231, 31801732, 74615404, 175433624, 413281276, 975355639, 2305763635, 5459480822, 12945857671 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,3`
	LINKS	`Index entries for sequences related to rooted trees` `Index entries for sequences related to trees`
	FORMULA	`G.f.: A(x) = x*cycle_index(S4, f), where f = A001190(x)/x.` `Cf. A000671.`
	CROSSREFS	`Sequence in context: A092603 A086125 A061030 * A145671 A108693 A007673` `Adjacent sequences: A036658 A036659 A036660 * A036662 A036663 A036664`
	KEYWORD	`nonn,easy`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com).`

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Last modified February 17 19:13 EST 2012. Contains 206085 sequences.