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%I #8 Apr 03 2023 10:36:11
%S 13,7,167,4079,47,2879,71850239,2444789759,21981381119,13357981992959,
%T 681004115066879,1136001594224639,16756459239477534719,
%U 781558105952602767359
%N Least prime that ends a complete Cunningham chain (of the first kind) of length n.
%C "Complete" means that this chain is not part of a longer Cunningham chain of the first kind.
%C Next term is greater than 4*10^17.
%C A005602(13)-> 8181864863026139 -> ... -> a(13) = 16756459239477534719. [From _Washington Bomfim_, Oct 21 2009]
%H Chris Caldwell's Prime Glossary, <a href="https://t5k.org/glossary/page.php?sort=CunninghamChain">Cunn ingham chains</a>.
%e 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.
%Y Cf. A005384, A005385, A007700, A023272, A023302, A023330, A059452, A057326, A059455, A059761, A059762, A059763, A059764, A074313.
%Y Cf. A110059 for Cunningham chains of the second kind.
%Y Cf. A005602 [From _Washington Bomfim_, Oct 21 2009]
%K nonn,hard
%O 1,1
%A _Alexandre Wajnberg_, Sep 04 2005
%E Edited and extended by _David Wasserman_, Aug 08 2006
%E a(13) and a(14) from _Washington Bomfim_, Oct 21 2009
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