[seqfan] Similar to a Cunningham Chain

[John W. Nicholson]

The following comes from Comments for A168421.
"For some n and k, we see that a(n) = A104272(k) as to form a chain of primes similar to a Cunningham chain. For example (and the first example), a(2) = 7, links A104272(2) = 11 = a(3), links A104272(3) = 17 = a(4), links A104272(4) = 29 = a(6), links A104272(6) = 47. Note that the links do not have to be of a form like q = 2*p+1 or q = 2*p-1. - John W. Nicholson, Dec 14 2013" What else can be said and what sequences can be stated? Can a program be made to find these chains?

John W. Nicholson