|
%I M1828 #13 May 11 2017 11:48:08
%S 1,1,1,2,8,16,384,768,3072,6144,1474560,589824,11796480,7864320,
%T 11890851840,23781703680,95126814720,27179089920,91321742131200,
%U 7305739370496,730573937049600,1461147874099200,385743038762188800,771486077524377600
%N Denominators of an asymptotic expansion for the number of forests on n nodes (A001858).
%C 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 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%D L. Takacs, On the number of distinct forests, SIAM J. Discrete Math., 3 (1990), 574-581.
%F 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 Cf. A006572, A001858, A111999.
%K nonn,frac
%O 0,4
%A _N. J. A. Sloane_.
%E a(10) and a(11) corrected and more terms from _Sean A. Irvine_, May 11 2017
|
