A214821 Number of genus 0 unsensed hypermaps with n darts.

1, 3, 6, 20, 57, 240, 954, 4566, 22641, 121823, 683307, 4004055

Offset: 1

Author

N. J. A. Sloane, Aug 01 2012

Keywords

• nonn
• more

Links

• Timothy R. Walsh, Space-efficient generation of nonisomorphic maps and hypermaps
• T. R. Walsh, Space-Efficient Generation of Nonisomorphic Maps and Hypermaps, J. Int. Seq. 18 (2015) # 15.4.3

Crossrefs

Cf. A090371, A118094, A214819, A214820, A057005; A214821-A214823, A215017, A215018.