notam n=5abcde
cel mai mic: 500000:491=1018 rest 162 =>n≥1019*491
cel mai mare:599999:491=1221 rest 488 => n≤1221*491
deci n∈{491*1019,491*1020,491*1021.....491*1221}
adica n∈{500329, 500820, 501311, ... ....599511}
Cate sunt?
Pai (1221-1019)+1= 203 de numere de tipul 5abcde
