OFFSET
-2,2
COMMENTS
Ramanujan's question 387 in the Journal of the Indian Mathematical Society (IV, 120) asked "Show that Sum_{k>=1} k/(exp(2*Pi*k) - 1) = 1/24 - 1/(8*Pi)".
REFERENCES
G. H. Hardy, P. V. Sheshu Aiyar and B. M. Wilson, Collected Papers of Srinivasa Ramanujan, Cambridge University Press, 1927, p. 326, Q. 427.
Oskar Schlömilch, Ueber einige unendliche Reihen, Sitzungsberichte der mathematisch-naturwissenschaftlichen Klasse der Sächsischen Akademie der Wissenschaften, Leipzig, 29 (1877), 101-105.
LINKS
B. C. Berndt, Y. S. Choi and S. Y. Kang, The problems submitted by Ramanujan to the Journal of Indian Math. Soc., in: Continued fractions, Contemporary Math., Vol. 236 (1999), pp. 15-56 (see Q387, JIMS IV).
B. C. Berndt, Y. S. Choi and S. Y. Kang, The problems submitted by Ramanujan to the Journal of Indian Math. Soc., in: Continued fractions, Contemporary Math., Vol. 236 (1999), pp. 15-56 (see Q387, JIMS IV).
S. Ramanujan, Question 387, Indian Mathematical Society (IV, 120).
C. C. Yalavigi, Problem H-176, Advanced Problems and Solutions, The Fibonacci Quarterly, Vol. 8, No. 5 (1970), p. 488; Keepeing the Q's on Cue, Solution to Problem H-176 by Clyde A. Bridger, ibid., Vol. 10, No. 2 (1972), pp. 186-190.
EXAMPLE
0.00187793089369283272444572582353807615805175523155255447974983...
MATHEMATICA
RealDigits[1/24 - 1/(8*Pi), 10, 100][[1]] (* Amiram Eldar, Feb 02 2022 *)
PROG
(PARI) 1/24 - 1/(8*Pi)
(PARI) suminf(k=1, k/(exp(2*Pi*k)-1))
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Hugo Pfoertner, Sep 24 2018
STATUS
approved