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URL: https://oeis.org/A220828

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A220828
Number of unrooted binary leaf-multi-labeled trees with n leaves on the label set [4].
2
4, 10, 20, 55, 220, 1040, 5480, 31420, 190360, 1202930, 7848720, 52543935, 359182620, 2498614620, 17640615900, 126142316865, 912047139460, 6658803466730, 49035674140240, 363881247076930, 2718918248334300, 20442286928323170, 154564065790535680, 1174669811887063830
OFFSET
1,1
LINKS
V. P. Johnson, Enumeration Results on Leaf Labeled Trees, Ph. D. Dissertation, Univ. Southern Calif., 2012.
CROSSREFS
Column 4 of A339649.
Sequence in context: A020149 A056412 A032275 * A015220 A047199 A038065
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 22 2012
EXTENSIONS
Terms a(11) and beyond from Andrew Howroyd, Dec 14 2020
STATUS
approved