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!)
A093003 Number of composite numbers among next n numbers. 0
0, 0, 2, 3, 3, 4, 6, 6, 6, 8, 9, 9, 10, 11, 12, 14, 13, 15, 16, 16, 17, 18, 19, 20, 21, 22, 23, 23, 24, 24, 27, 27, 30, 28, 29, 29, 32, 33, 33, 36, 33, 37, 37, 38, 37, 40, 39, 43, 42, 45, 40, 48, 47, 45, 48, 48, 48, 50, 52, 53, 52, 55, 55, 57, 53, 61, 58, 59, 58, 61, 64, 65, 61 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
FORMULA
comp(n(n+1)/2) - comp(n(n-1)/2), where comp(m) = number of composite numbers less than or equal to m.
EXAMPLE
a(5) = 3, among 11,12,13,14,15 there are three composite numbers 12,14 and 15.
CROSSREFS
Cf. A093004.
Sequence in context: A239964 A290585 A106464 * A348540 A118096 A296440
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Mar 29 2004
EXTENSIONS
Corrected and extended by Joshua Zucker, May 08 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 20 02:39 EDT 2024. Contains 372703 sequences. (Running on oeis4.)