OFFSET
1,2
EXAMPLE
Of 14 primes in 10th century, only 919 and 929 are consecutive primes with 10-gap, so a(10)=1.
CROSSREFS
KEYWORD
nonn
AUTHOR
Ki Punches, Mar 13 2009
EXTENSIONS
Edited and corrected by Ray Chandler, May 23 2009
STATUS
approved