OFFSET
1,1
COMMENTS
"Complete" means that this chain is not part of a longer Cunningham chain of the first kind.
Next term is greater than 4*10^17.
A005602(13)-> 8181864863026139 -> ... -> a(13) = 16756459239477534719. [From Washington Bomfim, Oct 21 2009]
LINKS
Chris Caldwell's Prime Glossary, Cunn ingham chains.
EXAMPLE
41->83->167 is a Cunningham chain of the first kind. It is complete because neither (41-1)/2 nor 2*167+1 is prime. It is the first such chain of three primes, so a(3) = 167.
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Alexandre Wajnberg, Sep 04 2005
EXTENSIONS
Edited and extended by David Wasserman, Aug 08 2006
a(13) and a(14) from Washington Bomfim, Oct 21 2009
STATUS
approved