A363846 - OEIS

A363846

Number of connected bipartite graphs on 2n nodes with a marked bipartite set of size n.

1, 1, 2, 13, 150, 3529, 194203, 29350896, 13668966399, 20662731749804, 103588456044907944, 1744955436868541083098, 99859125842603176324368784, 19611138475504485904873456937288, 13340730475029359536419515017040194246, 31706419735128559894860278029259121951682970, 265351742295121848168241791689670791068746978140331

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

COMMENTS

Also, number of n X n binary matrices up to permutations of rows and columns, representing the reduced adjacency matrices of connected bipartite graphs (cf. A002724).

LINKS

Max Alekseyev, Table of n, a(n) for n = 0..50

FORMULA

a(n) = A363845(2n, n).

CROSSREFS

Diagonal of the rectangular array described in A363845.

Cf. A002724, A028657, A123549.

Sequence in context: A364339 A204554 A069736 * A058192 A367820 A054382

Adjacent sequences: A363843 A363844 A363845 * A363847 A363848 A363849

KEYWORD

nonn

AUTHOR

Max Alekseyev, Jun 24 2023

STATUS

approved