A328889 Number of acyclic edge covers of the complete bipartite graph K_{n,n}.

1, 6, 132, 6728, 632970, 96208632, 21634786586, 6765592120576, 2811089200308642, 1498814096387846600, 997811910708863804202, 811362765374061475234464, 791392079095826028308709026, 912043721764132114072259699656, 1226095938791120621169019081161450

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..100

Eric Weisstein's World of Mathematics, Complete Bipartite Graph

Formula

a(n) ~ exp(1 - 2*exp(-1)) * n^(2*n-2). - Vaclav Kotesovec, Feb 10 2026

Crossrefs

Main diagonal of A328888.

Cf. A068087 (spanning trees).

Cf. A297077 (not necessarily covering edge sets).

Sequence in context: A174250 A395702 A277305 * A009688 A132872 A152289

Adjacent sequences: A328886 A328887 A328888 * A328890 A328891 A328892

Keyword

nonn

Author

Andrew Howroyd, Oct 29 2019

Status

approved