nu exista formula. e o suma care tinde la infinit
S = 1 + (1/2) + (1/3) + (1/4) + (1/5) + (1/6) + (1/7) + (1/8)+...
1/3 > 1/4
1/5 > 1/8 ; 1/6 > 1/8 ; 1/7 > 1/8
S > 1 + (1/2) + (1/4) + (1/4) + (1/8) + (1/8) + (1/8) + (1/8)+...
S > 1 + (1/2) + (1/2) + (1/2) +...
S> 1 + n/2, iar n tinde la infinit