One of the Plücker characteristics, defined by
 |
where 
is the class, 
the order, 
the number of nodes, 
the number of cusps, 
the number of stationary tangents (inflection
points), and 
the number of bitangents.
Curve Genus
See also
Riemann Curve TheoremExplore with Wolfram|Alpha
References
Coolidge, J. L. A Treatise on Algebraic Plane Curves. New York: Dover, p. 100, 1959.Referenced on Wolfram|Alpha
Curve GenusCite this as:
Weisstein, Eric W. "Curve Genus." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CurveGenus.html