A217671 a(n) is the least prime of the set of the smallest n consecutive primes a(n)=q_1(n), q_2(n),..., such that between (1/2)*q_i and (1/2)q_(i+1), i=1,...,n-1, there exists a prime, or a(n)=0 if no such set of primes exists.

3, 3, 3, 73, 523, 6581, 10753, 43103, 43103, 43103, 55457, 55457, 28751773, 278689963, 278689963, 784284211, 4440915607, 8340839629, 30651695947, 50246427391, 50246427391

Offset: 2

Author

Vladimir Shevelev, Oct 10 2012

Keywords

• nonn

Comments

If a(N) = 0, then a(n) = 0 for n > N. Conjecture 39 in the Shevelev link says that a(n) > 0.

Links

• V. Shevelev, Ramanujan and Labos primes, their generalizations, and classifications of primes, J. Integer Seq. 15 (2012) Article 12.5.4

Crossrefs

Cf. A166251, A182405, A182523, A182426.

Extensions

a(14) from John W. Layman and Hans Havermann

a(15)-a(17) from Carlos Rivera and Hans Havermann

a(18)-a(20) from Hans Havermann

a(21)-a(22) from Donovan Johnson, Oct 17 2012