A345258 Number of acyclic digraphs (or DAGs) on n unlabeled vertices with one source and one sink.

1, 1, 2, 10, 98, 1960, 80176, 6686760, 1129588960, 384610774696, 263104175114712, 360908867732030980, 991603865814038728388, 5453395569997436383751204, 60010050181461052836515513108, 1321051495313052133670927704328040, 58170762510305449187073353930875222256

Offset

1,3

Links

Andrew Howroyd, Table of n, a(n) for n = 1..50 (terms 1..40 from Mikhail Tikhomirov)

Marcel et al., Is there a formula for the number of st-dags (DAG with 1 source and 1 sink) with n vertices?, MathOverflow, 2021.

Prog

(PARI) A345258seq(16) \\ See PARI link in A122078 for program code.

Crossrefs

Row sums of A350491.

The labeled version is A165950.

Cf. A003087, A049531, A122078, A350415, A350492.

Sequence in context: A124214 A372235 A098279 * A355440 A248615 A276388

Adjacent sequences: A345255 A345256 A345257 * A345259 A345260 A345261

Keyword

nonn

Author

Max Alekseyev, Jun 12 2021

Extensions

a(9) from Brendan McKay.

Terms a(10) and beyond from Mikhail Tikhomirov, Jun 16 2021

Status

approved