A220827 - OEIS

%I #18 Dec 15 2020 12:53:09

%S 3,6,10,21,63,227,891,3876,17790,85536,424926,2169376,11312838,

%T 60065901,323746095,1767667332,9760149468,54422364834,306101712771,

%U 1735044593418,9902940693084,56876247586827,328516343529525,1907316302027081,11125942281844011,65182572852807465

%N Number of unrooted binary leaf-multi-labeled trees with n leaves on the label set [3].

%H Andrew Howroyd, <a href="/A220827/b220827.txt">Table of n, a(n) for n = 1..200</a>

%H V. P. Johnson, <a href="https://people.math.sc.edu/czabarka/Theses/JohnsonThesis.pdf">Enumeration Results on Leaf Labeled Trees</a>, Ph. D. Dissertation, Univ. Southern Calif., 2012.

%Y Column 3 of A339649.

%K nonn

%O 1,1

%A _N. J. A. Sloane_, Dec 22 2012

%E Terms a(11) and beyond from _Andrew Howroyd_, Dec 14 2020