OFFSET
0,1
COMMENTS
Decimal expansion of the double zeta function zeta(2,2). Not to be confused with the Hurwitz zeta function of two arguments or with the second derivative of the Riemann zeta function.
LINKS
R. E. Crandall and J. P. Buhler, On the evaluation of Euler sums, Exper. Math. 3 (1994), 275.
Wikipedia, Multiple zeta function
FORMULA
Equals Sum_{n >=2} Sum_{m=1..n-1} 1/(n*m)^2.
EXAMPLE
0.8117424... = A164109/40 .
MAPLE
evalf(Pi^4/120) ;
MATHEMATICA
First[RealDigits[Pi^4/120, 10, 100]] (* Geoffrey Critzer, Nov 03 2013 *)
PROG
(PARI) Pi^4/120 \\ Charles R Greathouse IV, Apr 17 2015
(PARI) zetamult([2, 2]) \\ Charles R Greathouse IV, Apr 17 2015
CROSSREFS
KEYWORD
AUTHOR
R. J. Mathar, Oct 10 2011
EXTENSIONS
More terms from D. S. McNeil, Oct 10 2011
Definition simplified by R. J. Mathar, Feb 05 2013
STATUS
approved