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 A050396 #19 Nov 07 2015 03:24:12 %S A050396 1,-1,1,1,-14,64,-97,-1376,15915,-68820,-467868,11504693,-85105325, %T A050396 -490922106,21504158897,-242026388646,-848338391966,80509815160192, %U A050396 -1351044945506956,1506218518200935,472249651021870475,-11783220545826576339,78093421491085905492 %N A050396 Exponential reversion of rooted trees A000081. %H A050396 Alois P. Heinz, <a href="/A050396/b050396.txt">Table of n, a(n) for n = 1..100</a> %H A050396 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a> %H A050396 <a href="/index/Res#revert">Index entries for reversions of series</a> %H A050396 <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a> %t A050396 a[n:0|1] := n; a[n_] := a[n] = Sum[m a[m] a[n-k*m], {m, n-1}, {k, (n-1)/m}]/(n-1); length = 20; Range[length]! InverseSeries[Sum[a[n] x^n/n!, {n, 0, length}] + O[x]^(length+1)][[3]] (* _Vladimir Reshetnikov_, Nov 06 2015 *) %Y A050396 Cf. A050395. %K A050396 sign %O A050396 1,5 %A A050396 _Christian G. Bower_, Nov 15 1999