A039506 Number of cluster primes less than 10^n.

3, 23, 99, 420, 1807, 8287, 40017, 202208, 1059807, 5736717, 31911465, 182019293, 1060723057

Offset: 1

Author

Christian G. Bower, Feb 15 1999

Keywords

• nonn
• more

Comments

The Blecksmith paper gives incorrect values of a(n) for n>8. - T. D. Noe, Jul 21 2006

Links

• Richard Blecksmith, Paul Erdős and J. L. Selfridge, Cluster Primes, Amer. Math. Monthly, 106 (1999), 43-48.
• Eric Weisstein's World of Mathematics, Cluster Prime.
• Wikipedia, Cluster prime.
• Index entries for sequences related to numbers of primes in various ranges

Crossrefs

Cf. A038133, A038134, A039507.

Cf. A121044, A121045 (cluster primes near 10^n).

Extensions

Corrected by T. D. Noe, Jul 21 2006