OFFSET
1,3
COMMENTS
Equals the value of the Dirichlet L-series of the non-principal character modulo 8 (A188510) at s=3. - Jianing Song, Nov 16 2019
REFERENCES
L. B. W. Jolley, Summation of series, Dover Publications Inc. (New York), 1961, p. 64 (formula 340).
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
R. J. Mathar, Table of Dirichlet L-series and prime zeta modulo functions for small moduli, Section 2.2 L(m=8, r=4, s=3).
FORMULA
Equals Sum_{i >= 0} (-1)^floor(i/2)/(2i+1)^3 = +1 +1/3^3 -1/5^3 -1/7^3 +1/9^3 +1/11^3 - ...
Equals Sum_{i >= 1} A188510(i)/i^3 = Sum_{i >= 1} Kronecker(-8,i)/i^3. - Jianing Song, Nov 16 2019
Equals 1/(Product_{p prime == 1 or 3 (mod 8)} (1 - 1/p^3) * Product_{p prime == 5 or 7 (mod 8)} (1 + 1/p^3)). - Amiram Eldar, Dec 17 2023
EXAMPLE
1.027722585936858567879256618002255767210100318536997465331084755185...
MATHEMATICA
RealDigits[3 Sqrt[2] Pi^3/128, 10, 90][[1]]
PROG
(PARI) 3*sqrt(2)*Pi^3/128 \\ G. C. Greubel, Jul 27 2018
(Magma) R:= RealField(); 3*Sqrt(2)*Pi(R)^3/128; // G. C. Greubel, Jul 27 2018
CROSSREFS
KEYWORD
AUTHOR
Bruno Berselli, Dec 10 2014
STATUS
approved