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 A081697 #13 Feb 04 2016 08:13:51 %S A081697 1,1,10,145,2755,64660,1804705,58336855,2141867440,87998832685, %T A081697 3998289746065,198991311832840,10762795518750121,628439018694857887, %U A081697 39390402253060922833,2637469071097179922603,187848412983167698626469,14178423030415044515701642 %N A081697 10-level labeled rooted trees with n leaves. %D A081697 J. Ginsburg, Iterated exponentials, Scripta Math., 11 (1945), 340-353. %D A081697 T. Hogg and B. A. Huberman, Attractors on finite sets: the dissipative dynamics of computing structures, Phys. Review A 32 (1985), 2338-2346. %H A081697 Alois P. Heinz, <a href="/A081697/b081697.txt">Table of n, a(n) for n = 0..360</a> %F A081697 E.g.f. exp(exp(exp(exp(exp(exp(exp(exp(exp(exp(x)-1)-1)-1)-1)-1)-1)-1)-1)-1). %o A081697 (PARI) a(n)=local(X); if(n<0,0,X=x+x*O(x^n); n!* %o A081697 polcoeff(exp(exp(exp(exp(exp(exp(exp(exp(exp(exp(X)-1)-1)-1)-1)-1)-1)-1)-1)-1),n)). %Y A081697 Cf. A000110, A000258, A000307, A000357, A001669. %Y A081697 Column k=9 of A144150. %K A081697 nonn %O A081697 0,3 %A A081697 _Benoit Cloitre_, Apr 23 2003