OFFSET
1,1
COMMENTS
What is exceptional in such neighborhoods of primorials is that in most cases no primes occur, i.e., these zones are peculiarly poor or empty of primes!
Primes are scarce in these zones because log(A002110(n)) < prime(n), so A002110(n)+1 and A002110(n)-1 are the only numbers in the neighborhood that are not divisible by one of the first n primes. - David Wasserman, Nov 16 2007
EXAMPLE
n=7: 7th primorial=510510; radius=14, a(7)=0 because there are no primes in the relevant neighborhood.
[1, 3], [4, 8], [26, 34], [2302, 2318] (around 2, 6, 30, 2310, respectively) are the only zones in which 2 primes were found.
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jul 14 2004
STATUS
approved