

A309329


Median of primes with n decimal digits.


4



4, 47, 509, 5273, 53047, 532887, 5356259, 53765483, 539119753, 5402600081, 54118210435, 541947386821, 5425907665571, 54313871643797, 543611236251491, 5440228524355329, 54438462600610510, 544705097744731559, 5449909581264135103
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OFFSET

1,1


COMMENTS

The number of ndigit primes < a(n) equals the number of ndigit primes > a(n). The median of an even number of values is understood to be defined as the arithmetic mean of the two central elements.


LINKS



FORMULA



EXAMPLE

a(1) = 4 because {2, 3, 5, 7} are the 4 onedigit primes. The 2 central elements of the sorted list are 3 and 5. 4 = (3 + 5)/2.
a(2) = 47 because it is the central element of the sorted list of the A006879(2) = 21 twodigit primes. There are 10 such primes < 47 and 10 such primes > 47.


CROSSREFS



KEYWORD

nonn,base,more


AUTHOR



STATUS

approved



