A309359 Median of the primes p with 2^(n-1) < p < 2^n.

6, 12, 23, 47, 97, 191, 383, 761, 1523, 3049, 6107, 12252, 24376, 48877, 97777, 195659, 391623, 783257, 1566386, 3133974, 6269116, 12538053, 25082361, 50170976, 100353498, 200730129, 401498897, 803081460, 1606292647, 3212862108

Offset

3,1

Comments

For n >= 3, median of the primes with n binary digits. The median of an even number of values is assumed to be defined as the arithmetic mean of the two central elements in their sorted list. The special case of the primes with two binary digits {2, 3} is excluded, because their median would be 5/2.

Links

Hugo Pfoertner, Table of n, a(n) for n = 3..63

Example

a(3) = 6: 2^2 < {5, 7} < 2^3, (5 + 7)/2 = 6.
a(4) = 12: 2^3 < {11, 13} < 2^4, (11 + 13)/2 = 12
a(5) = 23: 2^4 < {17, 19, 23, 29, 31} < 2^5, median = 23.

Crossrefs

Cf. A007053, A036378, A309329.

Sequence in context: A078472 A192754 A005694 * A172079 A081512 A096387

Adjacent sequences: A309356 A309357 A309358 * A309360 A309361 A309362

Keyword

nonn

Author

Hugo Pfoertner, Jul 25 2019

Status

approved