Ermakoff's Test
The series 
for a monotonic nonincreasing 
is convergent if
and divergent if
References
Bromwich, T. J. I'a and MacRobert, T. M. An Introduction to the Theory of Infinite Series, 3rd ed. New York: Chelsea, p. 43, 1991.
- Cholesky Decomposition
- Choose
- Choquet Theory
- Chord
- Chordal
- Chordal Theorem
- Chow Coordinates
- Chow Ring
- Chow Variety
- Christoffel-Darboux Formula
- Christoffel-Darboux Identity
- Christoffel Formula
- Christoffel Number
- Christoffel Symbol of the First Kind
- Christoffel Symbol of the Second Kind
- Chromatic Number
- Chromatic Polynomial
- Chu Identity
- Church's Theorem
- Church's Thesis
- Church-Turing Thesis
- Chu Space
- Chu-Vandermonde Identity
- Chvátal's Art Gallery Theorem
- Chvátal's Theorem