A018196 Possible numbers of complements of topologies on 5 points.

1, 4, 8, 9, 15, 32

Offset

0,2

Links

Table of n, a(n) for n=0..5.

J. I. Brown and S. Watson, The number of complements of a topology on n points is at least 2^n (except for some special cases), Discr. Math., 154 (1996), 27-39.

Crossrefs

Cf. A000798.

Sequence in context: A370999 A329728 A141066 * A396300 A072103 A004756

Adjacent sequences: A018193 A018194 A018195 * A018197 A018198 A018199

Keyword

nonn,more,fini

Author

N. J. A. Sloane

Status

approved