n : 35 = 13 ( resturile posibile sunt:0;1;2;3;...;34)
(restul impartirii < impartitorul 35) !
inseamna ca n = {13*35+0=455; 455+1=456; 457; ... ;488; 489)
[tex]455\,+\,455+1\,+\,455+2\,+\,...\,+\,455+33\,+\,455+34 =\\
=455\cdot35\,+\,1+2+3+...+34=455\cdot35\;+\;34\cdot35/2=35\cdot(455+17)=35\cdot472=16520[/tex]