A069738 Number of isomorphism classes of minimal n-extensions of a kind of homeomorphism of the circle.

1, 3, 7, 26, 97, 624, 4162, 34469

Offset

1,2

Comments

There is a formula in terms of conjugacy classes of transitive pairs and triples of permutations of degree n (A057005 and A057006).

References

N. G. Markley and W. N. Anderson,jun, An application of Moebius inversion to a problem in topological dynamics. Bull. Amer. Math. Soc. 79 (1973), 1027-1029.

V. A. Liskovets, On a combinatorial problem of the theory of topological transformations of the circle. Vesci AN BSSR (ser. fiz.-mat.), No 4 (1976), 29-34 (in Russian), Math. Rev. 58 #7575.

Links

Table of n, a(n) for n=1..8.

Crossrefs

Cf. A057005, A057006.

Sequence in context: A258311 A184459 A215018 * A057005 A158561 A252786

Adjacent sequences: A069735 A069736 A069737 * A069739 A069740 A069741

Keyword

more,nonn

Author

Valery A. Liskovets, Apr 15 2002

Status

approved