cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A170948 Number of chiral pairs of combinatorial maps with n edges.

Original entry on oeis.org

0, 0, 0, 0, 11, 226, 3597, 55006, 892791, 15763270, 305360481, 6483720916, 150200835113, 3774756521566, 102339496556342, 2977913930684928, 92579209306356230, 3062597993515937128, 107418845568842941190, 3981908640735783136040, 155550641755207044201203
Offset: 0

Views

Author

N. J. A. Sloane, Feb 21 2010

Keywords

Crossrefs

Cf. A170946 (sensed), A170947 (achiral), A214816 (unsensed).

Formula

a(n) = (A170946(n) - A170947(n)) / 2. [Breda d'Azevedo, Mednykh & Nedela, Corollary 4.8] - Andrey Zabolotskiy, Jun 06 2024

Extensions

Name clarified, a(0)=0 prepended and a(19) onwards added by Andrew Howroyd, Jan 27 2025