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 A277687 #18 Sep 04 2021 08:27:10 %S A277687 1,1,1,1,2,1,4,2,4,2,18,2,29,5,8,9,97,7,148,9,25,20 %N A277687 a(n) is the number of nonisomorphic trees on n vertices whose chromatic symmetric function in the p basis has a nonzero coefficient for each possible term. %C A277687 The path graph is always included in this count. %C A277687 The chromatic symmetric function is defined in Stanley (1995). By theorem 2.5 of that reference we can give an equivalent definition of this sequence. Say that a forest corresponds to the partition whose parts are the sizes of the trees in the forest. Then a(n) counts the trees on n vertices for which a forest corresponding to any partition of n can be produced by deleting edges from the tree. - _Peter J. Taylor_, Sep 03 2021 %H A277687 Richard P. Stanley, <a href="https://doi.org/10.1006/aima.1995.1020">A symmetric function generalization of the chromatic polynomial of a graph</a>, Advances in Math. 111 (1995), 166-194. %e A277687 For n = 5 there are three trees, but a(5) = 2 because the star tree cannot be split into a tree of size 2 and a tree of size 3. - _Peter J. Taylor_, Sep 03 2021 %Y A277687 Cf. A277686. %K A277687 nonn,more %O A277687 1,5 %A A277687 _Caleb Ji_, _Sam Heil_, Oct 26 2016 %E A277687 a(16)-a(22) from _Peter J. Taylor_, Sep 03 2021