OFFSET
0,2
LINKS
Derrick Norman Lehmer, Asymptotic Evaluation of Certain Totient Sums, American Journal of Mathematics, Vol. 22, No. 4 (1900), pp. 293-335.
Eric Weisstein's World of Mathematics, Primitive Pythagorean Triple.
FORMULA
Equals lim_{n->oo} A328499(n)/n. - Amiram Eldar, Jun 25 2021
Equals Integral_{z>=0} z*sech(Pi*z)^2. - Peter Luschny, Aug 03 2021
EXAMPLE
0.07023049277268287640...
MATHEMATICA
RealDigits[Log[2]/Pi^2, 10, 100][[1]] (* Amiram Eldar, Jun 25 2021 *)
PROG
(PARI) log(2)/Pi^2 \\ Michel Marcus, Jun 25 2021
CROSSREFS
KEYWORD
AUTHOR
Eric W. Weisstein, May 02 2006
STATUS
approved