A084955 Initial prime of a prime chain of length n under the iteration x->2x+5.

2, 3, 7, 13, 13, 13, 541, 4594309, 64649503, 7577449963, 2005324830163, 39676048812109, 272235769110157, 494535766350049

Offset

1,1

Comments

This is a special case of prime chains generated by f(x) = cx + d.

Links

Table of n, a(n) for n=1..14.

D. H. Lehmer, On certain chains of primes, Proc. London Math. Soc. (3) 14a 1965 183-186.

Example

a(3)=7 since 7, 2*7+5=19 and 2*19+5=43 are primes.

Crossrefs

Cf. A084954.

Sequence in context: A225093 A278007 A081256 * A273056 A026472 A286176

Adjacent sequences: A084952 A084953 A084954 * A084956 A084957 A084958

Keyword

nonn,more

Author

W. Edwin Clark, Jun 14 2003

Extensions

More terms from Don Reble, Nov 07 2007

Status

approved