Prime Cluster
A prime constellation, also called a prime k-tuple, prime k-tuplet, or prime cluster, is a sequence of k consecutive numbers such that the difference between the first and last is, in some sense, the least possible. More precisely, a prime k-tuplet is a sequence of consecutive primes (p_1, p_2, ..., p_k) with p_k - p_1 = s(k), where s(k) is the smallest number s for which there exist k integers b_1