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Mangoldt Function


MangoldtFunction

The Mangoldt function is the function defined by

 Lambda(n)={lnp   if n=p^k for p a prime; 0   otherwise,
(1)

sometimes also called the lambda function. exp(Lambda(n)) has the explicit representation

 e^(Lambda(n))=(LCM(1,2,...,n))/(LCM(1,2,...,n-1)),
(2)

where LCM(a,b,...) denotes the least common multiple. The first few values of exp(Lambda(n)) for n=1, 2, ..., plotted above, are 1, 2, 3, 2, 5, 1, 7, 2, ... (OEIS A014963).

The Mangoldt function is implemented in the Wolfram Language as MangoldtLambda[n].

It satisfies the divisor sums

sum_(d|n)mu(n/d)lnd=Lambda(n)
(3)
sum_(d|n)Lambda(d)=lnn
(4)
sum_(d|n)mu(d)lnd=-Lambda(n)
(5)
sum_(d|n)mu(n/d)Lambda(d)=-mu(n)lnn,
(6)

where mu(n) is the Möbius function (Hardy and Wright 1979, p. 254).

The Mangoldt function is related to the Riemann zeta function zeta(z) by

 -(zeta^'(s))/(zeta(s))=sum_(n=1)^infty(Lambda(n))/(n^s),
(7)

where Re[s]>1 (Hardy 1999, p. 28; Krantz 1999, p. 161; Edwards 2001, p. 50).

Its Mangoldt summatory function is denoted psi(x).


See also

Bombieri's Theorem, Chebyshev Functions, Explicit Formula, Greatest Prime Factor, Lambda Function, Landau's Formula, Least Common Multiple, Least Prime Factor, Mangoldt Summatory Function, Riemann Function

Explore with Wolfram|Alpha

References

Edwards, H. M. "Derivation of von Mangoldt's Formula for psi(x)." §3.2 in Riemann's Zeta Function. New York: Dover, pp. 50-54, 2001.Hardy, G. H. Ramanujan: Twelve Lectures on Subjects Suggested by His Life and Work, 3rd ed. New York: Chelsea, p. 28, 1999.Hardy, G. H. and Wright, E. M. An Introduction to the Theory of Numbers, 5th ed. Oxford, England: Clarendon Press, 1979.Havil, J. Gamma: Exploring Euler's Constant. Princeton, NJ: Princeton University Press, p. 109, 2003.Krantz, S. G. "The Lambda Function" and "Relation of the Zeta Function to the Lambda Function." §13.2.10 and 13.2.11 in Handbook of Complex Variables. Boston, MA: Birkhäuser, p. 161, 1999.Sloane, N. J. A. Sequence A014963 in "The On-Line Encyclopedia of Integer Sequences."

Referenced on Wolfram|Alpha

Mangoldt Function

Cite this as:

Weisstein, Eric W. "Mangoldt Function." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/MangoldtFunction.html

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