cp's OEIS Frontend

A134958 Number of hypertrees with n labeled vertices: analog of A030019 when edges of size 1 are allowed (with no two equal edges).

%I A134958 #6 Aug 21 2019 17:57:08
%S A134958 1,2,4,32,464,9952,284608,10207360,441006336,22312355840,
%T A134958 1294525492224,84749726259200,6181332806029312,497099907500220416,
%U A134958 43702202601439608832,4169993748235341529088,429217455330896263577600,47406138617171801211797504
%N A134958 Number of hypertrees with n labeled vertices: analog of A030019 when edges of size 1 are allowed (with no two equal edges).
%H A134958 Alois P. Heinz, <a href="/A134958/b134958.txt">Table of n, a(n) for n = 0..338</a>
%F A134958 Equals 2^n*A030019(n).
%p A134958 a:= n-> 2^n*`if`(n=0, 1, add(Stirling2(n-1, i)*n^(i-1), i=0...n-1)):
%p A134958 seq(a(n), n=0..18);  # _Alois P. Heinz_, Aug 21 2019
%K A134958 nonn
%O A134958 0,2
%A A134958 _Don Knuth_, Jan 26 2008