A395083 Number of relations R on an n-element set such that the transitive closure of R has exactly one element more than R.

0, 0, 2, 117, 5716, 368955, 33498576, 4327015126

Offset

0,3

Links

Table of n, a(n) for n=0..7.

Wikipedia, Transitive closure

Example

For n=0,1 the only relation is transitive (or has no missing pair to add), so a(0) = a(1) = 0.

Crossrefs

Cf. A006905.

Sequence in context: A188977 A042681 A024243 * A307094 A379549 A147774

Adjacent sequences: A395080 A395081 A395082 * A395084 A395085 A395086

Keyword

nonn,hard,more

Author

Firdous Ahmad Mala, May 10 2026

Extensions

a(6)-a(7) from Christian Sievers, May 20 2026

Status

approved