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.
- Whitehead's Theorem
- Whitney-Graustein Theorem
- Whitney-Mikhlin Extension Constants
- Whitney Singularity
- Whitney Sum
- Whitney Umbrella
- Whittaker Differential Equation
- Whittaker Function
- Whole Number
- Width (Partial Order)
- Width (Size)
- Wiedersehen Manifold
- Wieferich Prime
- Wielandt's Theorem
- Wiener Filter
- Wiener Function
- Wiener-Khintchine Theorem
- Wiener Measure
- Wiener Space
- Wigner 3j-Symbol
- Wigner 6j-Symbol
- Wigner 9j-Symbol
- Wigner-Eckart Theorem
- Wilbraham-Gibbs Constant
- Wilcoxon Rank Sum Test