A146170 Percentage (rounded) of odd numbers < 2^n which are primes or squarefree semiprimes.

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

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