Feit-Thompson Conjecture
Concerns Primes 
and 
for which 
and 
have a common factor. The only 
pair with bothvalues less than 400,000 is (17, 3313), with a common factor 112,643.
References
Wells, D. G. The Penguin Dictionary of Curious and Interesting Numbers. London: Penguin, p. 17, 1986.
- Brahmagupta Polynomial
- Brahmagupta's Formula
- Brahmagupta's Problem
- Braid
- Braid Group
- Braid Index
- Braid Word
- Braikenridge-Maclaurin Construction
- Branch
- Branch Cut
- Branch Line
- Branch Point
- Brauer Chain
- Brauer Group
- Brauer Number
- Brauer-Severi Variety
- Brauer's Theorem
- Braun's Conjecture
- Breeder
- Brelaz's Heuristic Algorithm
- Brent-Salamin Formula
- Brent's Factorization Method
- Brent's Method
- Bretschneider's Formula
- Brianchon Point