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A220818 Number of rooted binary MUL-trees with n leaves on the label set [5]. 2

%I

%S 5,15,75,495,3600,28275,232500,1979385,17287050,154041450,1394844375,

%T 12797919900,118722187125,1111672312125,10493033896875,99734572903680,

%U 953755379940150,9169941599036475,88588446263805000,859511126918229075,8371534717621838250

%N Number of rooted binary MUL-trees with n leaves on the label set [5].

%H Andrew Howroyd, <a href="/A220818/b220818.txt">Table of n, a(n) for n = 1..200</a>

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

%t a[n_] := a[n] = If[n < 2, 5 n, If[OddQ[n], 0, (# (1 - #)/2 &)[a[n/2]]] +

%t Sum[a[i] a[n - i], {i, 1, n/2}]];

%t Array[a, 25] (* _Jean-Fran├žois Alcover_, Sep 02 2019, after _Alois P. Heinz_ in A319539 *)

%Y Column 5 of A319539.

%K nonn

%O 1,1

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

%E Terms a(11) and beyond from _Andrew Howroyd_, Sep 23 2018

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Last modified September 27 09:09 EDT 2020. Contains 337380 sequences. (Running on oeis4.)