A027842 Number of subgroups of index n in fundamental group of a certain fiber space.

1, 7, 34, 227, 1296, 10576, 77554, 729379, 7013419, 77371042, 910455096, 11877617828, 165087132666, 2480783846184, 39677415301224, 675818886754115, 12180498014887816, 231893906693650507, 4645789707491981892, 97740610362119850762, 2153888078209948673032

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Links

• V. A. Liskovets and A. Mednykh, Enumeration of subgroups in the fundamental groups of orientable circle bundles over surfaces, Commun. in Algebra, 28, No. 4 (2000), 1717-1738.

Crossrefs

Cf. A027838, A027839, A027840, A060240.

Extensions

More terms from Sean A. Irvine, Dec 07 2019