Abundance
The abundance of a number 
is the quantity
where
is the Divisor Function. Kravitz has conjectured that no numbers exist whose abundance isan Odd Square (Guy 1994).The following table lists special classifications given to a number based on the value of 
.
| Number |
 | Deficient Number |
 | Almost Perfect Number |
| 0 | Perfect Number |
| 1 | Quasiperfect Number |
 | Abundant Number |
References
Guy, R. K. Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, pp. 45-46, 1994.
- Lifting Problem
- Ligancy
- Likelihood
- Likelihood Ratio
- Limaçon
- Limaçon Evolute
- Limaçon of Pascal
- Limit
- Limit Comparison Test
- Limit Cycle
- Limit Point
- Lindeberg Condition
- Lindeberg-Feller Central Limit Theorem
- Lindelof's Theorem
- Lindemann-Weierstraß Theorem
- Lindenmayer System
- Line
- Linear Algebra
- Linear Approximation
- Linear Code
- Linear Congruence
- Linear Congruence Method
- Linear Equation
- Linear Equation System
- Linear Extension