Legendre's constant named after Adrien-Marie Legendre
Legendre's constant is a mathematical constant occurring in a formula conjectured by Adrien-Marie Legendre to capture the asymptotic behavior of the prime-counting function 
  
    
      
        π
        (
        x
        )
      
    
    {\displaystyle \pi (x)}
  . Its value is now known to be 1.
Examination of available numerical evidence for known primes led Legendre to suspect that 
  
    
      
        π
        (
        x
        )
      
    
    {\displaystyle \pi (x)}
   satisfies an approximate formula.
Legendre conjectured in 1808 that
called after named for honored after called for