%I #17 Dec 15 2020 12:52:25
%S 0,0,1,6,30,140,663,3186,15642,78441,400842,2084698,11009358,58955139,
%T 319619706,1752122667,9700923252,54194387085,305216395077,
%U 1731579241287,9889280682948,56822058078669,328300135291659,1906449141877331,11122447670117451,65168427936552522
%N Number of unrooted binary leaf-multi-labeled trees with n leaves on the label set [3], with each label used at least once.
%H Andrew Howroyd, <a href="/A220830/b220830.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.
%F a(n) = A220827(n) - 3*A220826(n) + 3*A129860(n). - _Andrew Howroyd_, Dec 14 2020
%Y Column 3 of A339650.
%Y Cf. A129860, A220826, A220827, A220829.
%K nonn
%O 1,4
%A _N. J. A. Sloane_, Dec 22 2012
%E Terms a(11) and beyond from _Andrew Howroyd_, Dec 14 2020