This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A220826 #17 Dec 15 2020 12:54:22 %S A220826 2,3,4,6,12,31,78,234,722,2376,8046,28263,101226,370389,1375728, %T A220826 5182107,19743204,75994993,295110996,1155128397,4553360558, %U A220826 18063221619,72069527418,289053637621,1164871141254,4714973350560,19161577759814,78162897838290,319940064689142 %N A220826 Number of unrooted binary leaf-multi-labeled trees with n leaves on the label set [2]. %H A220826 Andrew Howroyd, <a href="/A220826/b220826.txt">Table of n, a(n) for n = 1..500</a> %H A220826 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. %o A220826 (PARI) U(30,2) \\ See A339649 for U(n,k). - _Andrew Howroyd_, Dec 14 2020 %Y A220826 Column 2 of A339649. %Y A220826 Cf. A083563, A220829. %K A220826 nonn %O A220826 1,1 %A A220826 _N. J. A. Sloane_, Dec 22 2012 %E A220826 Terms a(11) and beyond from _Andrew Howroyd_, Dec 14 2020