The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A000882 Number of twin prime pairs <= product of first n primes. 1
0, 1, 4, 15, 69, 468, 4636, 57453, 896062, 18463713, 425177757, 11997649372, 385088898632, 13280323588034, 509456736126003 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
Table of n, a(n) for n=1..15.
Tomás Oliveira e Silva, Tables of values of pi(x) and of pi2(x) [From Donovan Johnson, Mar 01 2010]
CROSSREFS
Cf. A002110, A000849.
Sequence in context: A125062 A039625 A020020 * A364908 A098614 A367040
Adjacent sequences: A000879 A000880 A000881 * A000883 A000884 A000885
KEYWORD
nonn,more,hard
AUTHOR
gandalf(AT)hrn.office.ssi.net (James D. Ausfahl)
EXTENSIONS
More terms from David W. Wilson
a(10)-a(15) from Donovan Johnson, Mar 01 2010
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 20 05:07 EDT 2024. Contains 372703 sequences. (Running on oeis4.)