Number of distinct topologies on an n-set that have exactly 9 open sets.
A281777
Number of distinct topologies on an n-set that have exactly 9 open sets.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =20a(5) =800a(6) =14260a(7) =189280a(8) =2181060a(9) =23241120a(10) =235737620a(11) =2308206560a(12) =21979728100a(13) =204477713440
External references
- oeis: A281777