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 A005355 M2680 #27 Jun 22 2018 23:07:39
%S A005355 0,1,1,1,3,7,21,61,187,577,1825,5831,18883,61699,203429,675545,
%T A005355 2258291,7592249,25656477,87096661,296891287,1015797379,3487272317,
%U A005355 12008898531,41471260883,143588078449,498343911529,1733410858955,6041795275027,21098924740155
%N A005355 Number of asymmetric permutation rooted trees with n nodes.
%D A005355 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A005355 Alois P. Heinz, <a href="/A005355/b005355.txt">Table of n, a(n) for n = 0..1000</a>
%H A005355 Gilbert Labelle, <a href="http://dx.doi.org/10.1016/0747-7171(92)90037-5">Counting asymmetric enriched trees</a>, J. Symbolic Comput. 14 (1992), no. 2-3, 211-242.
%H A005355 <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a>
%F A005355 Shifts left under transform T where Ta has g.f. (1-A(x^2))/(1-A(x)).
%t A005355 a[0] = 1; a[1] = 1; a[n_] := a[n] = Sum[a[k]*a[n-k], {k, 1, n-1}] - If[EvenQ[n-1], a[(n-1)/2], 0]; Table[a[n], {n, 0, 27}] (* _Jean-François Alcover_, Jan 04 2016 *)
%Y A005355 Cf. A004111, A050383.
%K A005355 nonn,nice,easy,eigen
%O A005355 0,5
%A A005355 _N. J. A. Sloane_, _Simon Plouffe_, _Susanna Cuyler_
%E A005355 More terms, formula from _Christian G. Bower_, Nov 15 1999