A011272 - OEIS

%I #11 Apr 02 2015 17:29:13

%S 0,1,3,13,64,339,1885,10851,64109,386510,2368354,14706331,92337618,

%T 585239903,3739309053,24059542845,155756019048,1013801283133,

%U 6630587014935,43553555324502

%N Hybrid binary rooted trees with n nodes whose root is labeled by "a".

%H Nancy S. S. Gu, Nelson Y. Li, and Toufik Mansour, <a href="http://dx.doi.org/10.1016/j.disc.2007.04.007">2-Binary trees: bijections and related issues</a>, Discr. Math., 308 (2008), 1209-1221.

%H J. M. Pallo, <a href="http://dx.doi.org/10.1080/00207169408804251">On the listing and random generation of hybrid binary trees</a>, International Journal of Computer Mathematics, 50 (1994) 135-145.

%H <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a>

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

%K nonn

%O 0,3

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