OFFSET
0,1
LINKS
Eckford Cohen, Arithmetical functions associated with the unitary divisors of an integer, Mathematische Zeitschrift, Vol. 74, No. 1 (1960), pp. 66-80.
R. Sitaramachandrarao and D. Suryanarayana, On Sigma_{n<=x} sigma*(n) and Sigma_{n<=x} phi*(n), Proceedings of the American Mathematical Society, Vol. 41, No. 1 (1973), pp. 61-66.
FORMULA
EXAMPLE
0.68421638881010293786838292699239597056540695732620...
MATHEMATICA
RealDigits[Pi^2/12/Zeta[3], 10, 100][[1]]
PROG
(PARI) Pi^2/(12*zeta(3)) \\ Michel Marcus, May 19 2020
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Amiram Eldar, May 19 2020
STATUS
approved