A309359 - OEIS

%I #15 Jul 27 2019 12:17:52

%S 6,12,23,47,97,191,383,761,1523,3049,6107,12252,24376,48877,97777,

%T 195659,391623,783257,1566386,3133974,6269116,12538053,25082361,

%U 50170976,100353498,200730129,401498897,803081460,1606292647,3212862108

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

%C 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.

%H Hugo Pfoertner, <a href="/A309359/b309359.txt">Table of n, a(n) for n = 3..63</a>

%e a(3) = 6: 2^2 < {5, 7} < 2^3, (5 + 7)/2 = 6.

%e a(4) = 12: 2^3 < {11, 13} < 2^4, (11 + 13)/2 = 12

%e a(5) = 23: 2^4 < {17, 19, 23, 29, 31} < 2^5, median = 23.

%Y Cf. A007053, A036378, A309329.

%K nonn

%O 3,1

%A _Hugo Pfoertner_, Jul 25 2019