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Difference between the number of primes with n digits (A006879) and the difference of consecutive integers nearest to Li(10^n) - Li(2) (see A228067).
5

%I #14 Apr 18 2021 22:01:56

%S -1,-3,-5,-7,-21,-92,-209,-415,-947,-1403,-8484,-26675,-70708,-205919,

%T -737729,-2162013,-4741957,-13992966,-77928220,-122866869,-374649610,

%U -1334960954,-5317831008,-9896721062,-38014073661

%N Difference between the number of primes with n digits (A006879) and the difference of consecutive integers nearest to Li(10^n) - Li(2) (see A228067).

%C The sequence A006879(n) is always < A228067(n) for 1 <= n <= 25.

%C The sequence (A228067) yields an average relative difference in absolute value, i.e., average(abs(A228068(n))/A006879(n) = 0.0175492... for 1 <= n <= 25.

%C Note that A190802(n) = (Li(10^n) - Li(2)) is not defined for n=0. Its value is set arbitrarily to 0.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeCountingFunction.html">Prime Counting Function</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/LogarithmicIntegral.html">Logarithmic Integral</a>

%F a(n) = A006879(n) - A228067(n).

%Y Cf. A006880, A006879, A228067, A228066.

%K sign

%O 1,2

%A _Vladimir Pletser_, Aug 06 2013