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.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A146170 Percentage (rounded) of odd numbers < 2^n which are primes or squarefree semiprimes. 0
 0, 50, 75, 75, 75, 78, 78, 77, 75, 72, 70, 66, 64, 61, 59, 57, 55, 53, 51, 49, 48, 46, 45, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..33. FORMULA a(n) = round((A146168(n)+A007053(n)-1)/(2^(n-1))*100). EXAMPLE a(4)=75 because 75% of the 2^3 numbers 1, 3, 5, 7, 9, 11, 13 and 15 are primes or squarefree semiprimes. CROSSREFS Cf. A001358(semiprimes), A007053(Number of primes <= 2^n), A146168(Number of odd squarefree semiprimes < 2^n). Sequence in context: A224552 A039473 A309123 * A367708 A217857 A071366 Adjacent sequences: A146167 A146168 A146169 * A146171 A146172 A146173 KEYWORD nonn AUTHOR Washington Bomfim, Oct 27 2008 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.

Last modified May 17 19:53 EDT 2024. Contains 372607 sequences. (Running on oeis4.)