Quasiperfect Number
A least Abundant Number, i.e., one such that
Quasiperfect numbers are therefore the sum of their nontrivial Divisors. No quasiperfect numbers areknown, although if any exist, they must be greater than
and have seven or moreDivisors. Singh (1997) called quasiperfect numbers Slightly Excessive Numbers.See also Abundant Number, Almost Perfect Number, Perfect Number
References
Guy, R. K. ``Almost Perfect, Quasi-Perfect, Pseudoperfect, Harmonic, Weird, Multiperfect and Hyperperfect Numbers.'' §B2 in Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, pp. 45-53, 1994. Singh, S. Fermat's Enigma: The Epic Quest to Solve the World's Greatest Mathematical Problem. New York: Walker, p. 13, 1997.
- Dual Basis
- Dual Bivector
- Dual Graph
- Duality Principle
- Duality Theorem
- Dual Map
- Dual Polyhedron
- Dual Scalar
- Dual Solid
- Dual Tensor
- Dual Voting
- Du Bois Raymond Constants
- Duffing Differential Equation
- Duhamel's Convolution Principle
- Dumbbell Curve
- Duodecillion
- Dupin's Cyclide
- Dupin's Indicatrix
- Dupin's Theorem
- Duplication Formula
- Duplication of the Cube
- Durand's Rule
- Durfee Polynomial
- Durfee Square
- Dvoretzky's Theorem