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 A184164 #20 Jul 08 2025 12:26:47 %S A184164 2,4,5,7,8,9,12,13,14,16,18,19,22,23,26,27,29,31,33,35,38,39,42,43,46, %T A184164 50,52,54,60,65,68,72,77,89 %N A184164 List of numbers that are not the number of subtrees of some tree. %C A184164 This is a finite list of 34 numbers. %H A184164 Éva Czabarka, László Székely, and Stephan Wagner, <a href="https://doi.org/10.1016/j.dam.2009.07.004">The inverse problem for certain tree parameters</a>, Discrete Appl. Math., 157, 2009, 3314-3319, section 2.6. %H A184164 Ryan McCulloch, Brendan D. McKay, Alireza Salahshoori, and Thomas Zaslavsky, <a href="https://arxiv.org/abs/2507.02260">The Cycle Counts of Graphs</a>, arXiv:2507.02260 [math.CO], 2025. See p. 7. %e A184164 4 and 5 are in the sequence since the 2-vertex tree has 3 subtrees and an m-vertex tree (m>=3) has at least 6 subtrees. %Y A184164 Cf. A344406 (caterpillars). %K A184164 nonn,fini,full %O A184164 1,1 %A A184164 _Emeric Deutsch_, Oct 19 2011