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Liouville Summatory Function


LiouvilleL

The Liouville summatory function is the summatory function

 L(n)=sum_(k=1)^nlambda(k),
(1)

where lambda(k) is the Liouville function. Its first values for n=1, 2, ... are 1, 0, -1, 0, -1, 0, -1, -2, -1, 0, -1, -2, -3, -2, -1, 0, -1, -2, -3, -4, ... (OEIS A002819).

Lehman (1960) gives the formulas

 L(x)=sum_(m=1)^(x/w)mu(m){|_sqrt(x/m)_|-sum_(k=1)^(v-1)lambda(k)(|_x/(km)_|-|_x/(mv)_|)}
-sum_(l=x/w-1)^(x/v)L(x/l)sum_(m|l; m=1)^(x/w)mu(m)
(2)

and

 L(x)=sum_(k=1)^gM(x/(k^2))+sum_(l=1)^(x/g^2)mu(l)|_sqrt(x/l)_|-M(x/(g^2))|_sqrt(x/(g^2))_|,
(3)

where k, l, and m range over the positive integers, mu(n) is the Möbius function, M(x) is the Mertens function, and v, w, and x are positive real numbers with v<w<x.

The refuted Pólya conjecture asserted that L(n)<=0 for all n>=2. The first positive value occurs at n=906150257 (Tanaka 1980). The first zeros are 2, 4, 6, 10, 16, 26, 40, 96, 586, 906150256, 906150294, 906150308, 906150310, 906150314, 906151516, ... (OEIS A028488). It is not known whether L(x) changes sign infinitely often.

The values of L(10^n) for n=0, 1, 2, ... are 1, 0, -2, -14, -94, -288, -530, -842, -3884, ... (OEIS A090410).


See also

Liouville Function, Mertens Function, Pólya Conjecture, Summatory Function

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References

Fawaz, A. Y. "The Explicit Formula for L_0(x)." Proc. London Math. Soc. 1, 86-103, 1951.Gupta, H. "On a Table of Values of L(n)." Proc. Indian Acad. Sci. Sec. A 12, 407-409, 1940.Gupta, H. "A Table of Values of Liouville's Function L(n)." Res. Bull. East Panjab University, No. 3, 45-55, 1950.Lehman, R. S. "On Liouville's Function." Math. Comput. 14, 311-320, 1960.Ramanujan, S. "Irregular Numbers." J. Indian Math. Soc. 5, 105-106, 1913.Ramanujan, S. Collected Papers of Srinivasa Ramanujan (Ed. G. H. Hardy, P. V. S. Aiyar, and B. M. Wilson). Providence, RI: Amer. Math. Soc., pp. 20-21, 2000.Ribenboim, P. Algebraic Numbers. New York: Wiley, p. 44, 1972.Roberts, J. The Lure of the Integers. Washington, DC: Math. Assoc. Amer., p. 279, 1992.Sloane, N. J. A. Sequences A002819/M0042, A028488, and A090410 in "The On-Line Encyclopedia of Integer Sequences."Tanaka, M. "A Numerical Investigation on Cumulative Sum of the Liouville Function." Tokyo J. Math. 3, 187-189, 1980.

Cite this as:

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

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