'Strange' occurrences in SuperEnalotto

In this paper a way is suggested for calculating the probability of consecutive number strings within a sequence of n numbers randomly drawn (without replacement) among the set of the first N consecutive numbers, with N»n. An explicit derivation is carried out for the special case of SuperEnalotto, nowadays the most famous lottery in Italy, with N=90 and n=6. It turns out that, on average, one every three drawings presents one or more consecutive number strings inside.