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 A006573 M1828 #17 Jul 08 2025 16:49:49
%S A006573 1,1,1,2,8,16,384,768,3072,6144,1474560,589824,11796480,7864320,
%T A006573 11890851840,23781703680,95126814720,27179089920,91321742131200,
%U A006573 7305739370496,730573937049600,1461147874099200,385743038762188800,771486077524377600
%N A006573 Denominators of an asymptotic expansion for the number of forests on n nodes (A001858).
%C A006573 Takacs Table 2 gives incorrect A006572(10)/A006573(10) = -137483257/61440 and A006572(11)/A006573(11) = -24971924401/983040. - _Sean A. Irvine_, May 11 2017
%D A006573 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%D A006573 L. Takacs, On the number of distinct forests, SIAM J. Discrete Math., 3 (1990), 574-581.
%F A006573 a(n) = denom(Sum_{i=1..floor(n/2)} (-1)^(i-1) * |A111999(n, 2*i-1)| / (2^(n-i) * (n-i)!)). - _Sean A. Irvine_, May 11 2017
%Y A006573 Cf. A006572, A001858, A111999.
%K A006573 nonn,frac
%O A006573 0,4
%A A006573 _N. J. A. Sloane_
%E A006573 a(10) and a(11) corrected and more terms from _Sean A. Irvine_, May 11 2017