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 A339302 #8 Dec 08 2020 15:24:03 %S A339302 1,2,8,22,69,194,564,1584,4484,12550,35204,98412,275422,770416, %T A339302 2157334,6044684,16956389,47614380,133865184,376789710,1061822884, %U A339302 2995785714,8461975888,23928712708,67739408492,191964821890,544559201634,1546306248630,4394984617389 %N A339302 Number of unlabeled rooted trees with n nodes rooted at two indistinguishable nodes at distance 3 from each other. %C A339302 Number of unoriented linear forests with n nodes and 4 rooted trees. %H A339302 Andrew Howroyd, <a href="/A339302/b339302.txt">Table of n, a(n) for n = 4..500</a> %F A339302 G.f.: (r(x)^4 + r(x^2)^2)/2 where r(x) is the g.f. of A000081. %Y A339302 Cf. A000081. %Y A339302 Column 4 of A339303. %K A339302 nonn %O A339302 4,2 %A A339302 _Andrew Howroyd_, Dec 04 2020