Ore's Conjecture
Define the Harmonic Mean of the Divisors of 
where
is the Tau Function (the number of Divisors of ). If is a PerfectNumber, 
is an Integer. Ore conjectured that if is Odd, then is not an Integer. Thisimplies that no Odd Perfect Numbers exist.See also Harmonic Divisor Number, Harmonic Mean, Perfect Number, Tau Function- Sublime Number
- Submanifold
- Submatrix
- Subnormal
- Subordinate Norm
- Subscript
- Subsequence
- Subset
- Subspace
- Substitution Group
- Substitution Map
- Subtend
- Subtraction
- Succeeds
- Successes
- Sufficient
- Suitable Number
- Sum
- Summand
- Summatory Function
- Sum-Product Number
- Sum Rule
- Sup
- Characteristic (Partial Differential Equation)
- Characteristic Polynomial