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

1, 2, 4, 32, 464, 9952, 284608, 10207360, 441006336, 22312355840, 1294525492224, 84749726259200, 6181332806029312, 497099907500220416, 43702202601439608832, 4169993748235341529088, 429217455330896263577600, 47406138617171801211797504

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..338

Formula

Equals 2^n*A030019(n).

Maple

a:= n-> 2^n*`if`(n=0, 1, add(Stirling2(n-1, i)*n^(i-1), i=0...n-1)):
seq(a(n), n=0..18);  # Alois P. Heinz, Aug 21 2019

Crossrefs

Sequence in context: A144937 A009110 A225170 * A101460 A304862 A118992

Adjacent sequences: A134955 A134956 A134957 * A134959 A134960 A134961

Keyword

nonn

Author

Don Knuth, Jan 26 2008

Status

approved