@article{05068464,
title = {The number of topologies on a finite set.},
journal = {Journal of Integer Sequences [electronic only]},
volume = {9},
year = {2006},
zbl = {1103.11007},
language = {en},
url = {http://dml.mathdoc.fr/item/05068464}
}
Benoumhani, Moussa. The number of topologies on a finite set.. Journal of Integer Sequences [electronic only], Tome 9 (2006) . http://gdmltest.u-ga.fr/item/05068464/