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

Author

W. Edwin Clark, Jun 14 2003

Keywords

• nonn
• more

Comments

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

Examples

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

Links

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

Crossrefs

Cf. A084954.

Extensions

More terms from Don Reble, Nov 07 2007