OFFSET
1,2
COMMENTS
The constant c in the asymptotic formulas Sum_{n1, n2 <= x} sigma(lcm(n1, n2)) = c * x^4/4 + O(x^(7/2 + eps)) and Sum_{n1, n2 <= x} sigma(lcm(n1, n2))/(n1*n2) = c * x^2 + O(x^(3/2 + eps)).
LINKS
Titus Hilberdink and László Tóth, On the average value of the least common multiple of k positive integers, Journal of Number Theory, Vol. 169 (2016), pp. 327-341. See p. 333.
EXAMPLE
1.38692417041356586898814919766510683616526207826392...
MATHEMATICA
$MaxExtraPrecision = 1500; m = 1500; c = LinearRecurrence[{0, -1, 2, 0, 2, -2}, {0, 2, -6, -2, 0, 2}, m]; Zeta[3] * Zeta[4] * Exp[NSum[Indexed[c, n]*PrimeZetaP[n]/n, {n, 2, m}, NSumTerms -> m, WorkingPrecision -> m]]
PROG
(PARI) zeta(3) * zeta(4) * prodeulerrat(1 + 1/p^2 - 2/p^3 - 2/p^5 + 2/p^6)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Amiram Eldar, Feb 18 2021
STATUS
approved