COPRIMALITY CRITERION OF SMARANDACHE     

     


     Let a and b be strictly positive coprime integers.  Then:

                   F(b)+1     F(a)+1
                  a       +  b       is congruent to  a + b ( mod ab ),

     where F is Euler's totient function.


References:
 [1] Dumitrescu, C., Seleacu, V., "Some notions and questions in number
     theory", Erhus Univ. Press, Glendale, 1994, Section #118 ("Smarandache
     Criterion of Coprimality").
 [2] Smarandache, Florentin, "Collected Problems of Mathematics", University
     of Kishinev Press, Kishinev, 1997, Problem 37, p. 26.