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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

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 * A217857 A071366 A321517

Adjacent sequences:  A146167 A146168 A146169 * A146171 A146172 A146173

KEYWORD

nonn

AUTHOR

Washington Bomfim, Oct 27 2008

STATUS

approved

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Last modified December 3 05:05 EST 2021. Contains 349445 sequences. (Running on oeis4.)