The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A245058 Decimal expansion of the real part of Li_2(I), negated. 5
 2, 0, 5, 6, 1, 6, 7, 5, 8, 3, 5, 6, 0, 2, 8, 3, 0, 4, 5, 5, 9, 0, 5, 1, 8, 9, 5, 8, 3, 0, 7, 5, 3, 1, 4, 8, 6, 5, 2, 3, 6, 8, 7, 3, 7, 6, 5, 0, 8, 4, 9, 8, 0, 4, 7, 1, 6, 9, 4, 4, 7, 7, 8, 6, 7, 1, 2, 5, 0, 9, 3, 3, 8, 0, 0, 4, 0, 0, 1, 0, 9, 2, 2, 9, 2, 0, 3, 6, 1, 2, 5, 7, 7, 4, 6, 9, 8, 3, 8, 1, 6, 3, 0, 0, 0 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS This is the decimal expansion of the real part of the dilogarithm of the square root of -1. The imaginary part is Catalan's number (A006752). LINKS G. C. Greubel, Table of n, a(n) for n = 0..10000 (terms 0..104 from Robert G. Wilson v) FORMULA Also equals -zeta(2)/8 = -Pi^2/48. Also equals the Bessel moment Integral_{0..inf} x I_1(x) K_0(x)^2 K_1(x) dx. - Jean-François Alcover, Jun 05 2016 From Terry D. Grant, Sep 11 2016: (Start) Equals Sum_{n>=0} (-1)^n/(2n+2)^2. Equals (Sum_{n>=1} 1/(2n)^2)/2 = A222171/2. (End) Equals Sum_{k>=1} A007949(k)/k^2. - Amiram Eldar, Jul 13 2020 EXAMPLE 0.2056167583560283045590518958307531486523687376508498047169447786712509338004... MATHEMATICA RealDigits[ Re[ PolyLog[2, I]], 10, 111][[1]] (* or *) RealDigits[ Zeta[2]/8, 10, 111][[1]] (* or *) RealDigits[ Pi^2/48, 10, 111][[1]] PROG (PARI) zeta(2)/8 \\ Charles R Greathouse IV, Aug 27 2014 (Sage) (pi**2/48).n(200) # F. Chapoton, Mar 16 2020 (MAGMA) SetDefaultRealField(RealField(100)); R:=RealField(); Pi(R)^2/48; // G. C. Greubel, Aug 25 2018 CROSSREFS Cf. A006752, A007949, A072691, A222171, A242301. Sequence in context: A155524 A051111 A068558 * A240657 A262420 A240662 Adjacent sequences:  A245055 A245056 A245057 * A245059 A245060 A245061 KEYWORD nonn,cons AUTHOR Robert G. Wilson v, Aug 21 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 10 06:54 EDT 2021. Contains 342843 sequences. (Running on oeis4.)