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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
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
KEYWORD
nonn
AUTHOR
Washington Bomfim, Oct 27 2008
STATUS
approved

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