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A011272 Hybrid binary rooted trees with n nodes whose root is labeled by "a". 2
0, 1, 3, 13, 64, 339, 1885, 10851, 64109, 386510, 2368354, 14706331, 92337618, 585239903, 3739309053, 24059542845, 155756019048, 1013801283133, 6630587014935, 43553555324502 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..19.

Nancy S. S. Gu, Nelson Y. Li, and Toufik Mansour, 2-Binary trees: bijections and related issues, Discr. Math., 308 (2008), 1209-1221.

J. M. Pallo, On the listing and random generation of hybrid binary trees, International Journal of Computer Mathematics, 50 (1994) 135-145.

Index entries for sequences related to rooted trees

FORMULA

a(n) = A007863(n) - A011270(n).

CROSSREFS

Sequence in context: A292183 A006923 A283667 * A200719 A065065 A020086

Adjacent sequences:  A011269 A011270 A011271 * A011273 A011274 A011275

KEYWORD

nonn

AUTHOR

Jean Pallo (pallo(AT)u-bourgogne.fr)

STATUS

approved

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Last modified April 19 19:11 EDT 2019. Contains 322290 sequences. (Running on oeis4.)