login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A039507 Number of odd non-cluster primes less than 10^n. 3
0, 1, 68, 808, 7784, 70210, 624561, 5559246, 49787726, 449315793, 4086143347, 37425892724, 345004813781 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

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

LINKS

Table of n, a(n) for n=1..13.

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.

Index entries for sequences related to numbers of primes in various ranges

FORMULA

a(n) = A006880(n) - A039506(n) - 1. - T. D. Noe, Jul 21 2006

CROSSREFS

Cf. A038133, A038134, A039506.

Sequence in context: A244440 A166398 A200876 * A250144 A250338 A223374

Adjacent sequences:  A039504 A039505 A039506 * A039508 A039509 A039510

KEYWORD

nonn,more

AUTHOR

Christian G. Bower, Feb 15 1999

EXTENSIONS

Corrected by T. D. Noe, Jul 21 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 11 15:11 EDT 2021. Contains 343791 sequences. (Running on oeis4.)