OFFSET
1,1
COMMENTS
Conjecture: the set of k such that a(k+1)-a(k)=2 is infinite.
FORMULA
If a(k+1)-a(k)=2 then a(k) or a(k+1) is prime. For example : a(9)-a(8)=37-35 and a(9)=37 is prime. a(16)-a(15)=69-67=2 and a(15)=67 is prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jan 16 2002
STATUS
approved