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A363846
Number of connected bipartite graphs on 2n nodes with a marked bipartite set of size n.
4
1, 1, 2, 13, 150, 3529, 194203, 29350896, 13668966399, 20662731749804, 103588456044907944, 1744955436868541083098, 99859125842603176324368784, 19611138475504485904873456937288, 13340730475029359536419515017040194246, 31706419735128559894860278029259121951682970, 265351742295121848168241791689670791068746978140331
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
FORMULA
a(n) = A363845(2n, n).
CROSSREFS
Diagonal of the rectangular array described in A363845.
Sequence in context: A364339 A204554 A069736 * A058192 A367820 A054382
KEYWORD
nonn
AUTHOR
Max Alekseyev, Jun 24 2023
STATUS
approved