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A282870
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a(n) = floor( Li(n) - pi(n) ).
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2
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0, 0, 0, 0, 1, 0, 1, 1, 2, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 2, 2, 2, 3, 3, 2, 3, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 3, 3, 3, 3, 3, 3, 4, 4, 3, 3, 4, 4, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 4, 4, 3, 3, 4, 4, 4, 4, 5, 5, 4, 4, 4, 5, 4, 4, 3, 3, 4, 4
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OFFSET
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2,9
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COMMENTS
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Li(x) is the logarithmic integral of x.
pi(x) is the number of primes less than or equal to x, A000720(x).
"The Riemann hypothesis is an assertion about the size of the error term in the prime number theorem, namely, that pi(x) = li(x)+O(x^(1/2+epsilon))", see Nathanson, page 323.
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REFERENCES
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Melvyn B. Nathanson, Elementary Methods in Number Theory, Springer, 2000
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LINKS
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FORMULA
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MAPLE
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a:= n-> floor(evalf(Li(n)))-numtheory[pi](n):
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MATHEMATICA
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iend = 100;
For[x = 1, x <= iend, x++,
a[x] = N[LogIntegral[x] - PrimePi[x]]]; t =
Table[Floor[a[i]], {i, 2, iend}]; Print[t]
Table[Floor[LogIntegral[n] - PrimePi[n]], {n, 2, 110}] (* G. C. Greubel, May 17 2019 *)
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PROG
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(PARI) vector(110, n, n++; floor(real(-eint1(-log(n))) - primepi(n)) ) \\ G. C. Greubel, May 17 2019
(Magma) [Floor(LogIntegral(n) - #PrimesUpTo(n)): n in [2..110]]; // G. C. Greubel, May 17 2019
(Sage) [floor(li(n) - prime_pi(n)) for n in (2..110)] # G. C. Greubel, May 17 2019
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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