A226735 Decimal expansion of Sum_{k>=0} (-1)^k * (3*k + 1)^(-3).

9, 8, 6, 5, 9, 0, 9, 8, 6, 2, 6, 2, 5, 4, 2, 2, 9, 1, 3, 0, 3, 2, 0, 5, 5, 3, 4, 1, 4, 5, 7, 3, 9, 3, 2, 0, 9, 5, 2, 0, 4, 4, 7, 4, 9, 6, 6, 8, 7, 1, 6, 9, 8, 5, 9, 9, 7, 4, 3, 7, 4, 1, 8, 0, 9, 1, 6, 3, 8, 8, 6, 6, 2, 0, 7, 5, 5, 1, 1, 6, 3, 3, 4, 1, 4, 4, 4, 9, 4, 9, 3, 7, 4, 2, 4, 5, 9, 4, 3, 6, 0, 7, 5, 5, 3

Offset

0,1

Links

Table of n, a(n) for n=0..104.

R. W. Gosper, Acceleration of series, AI memo 304 (1974), page 40

Formula

Equals (10*Sqrt(3)*Pi^3 + 351*zeta(3))/972.

Example

0.986590986262542291303205534145739320952044749668716985997437418...

Mathematica

RealDigits[N[Sum[(-1)^k (3k + 1)^(-3), {k, 0, Infinity}], 10, 105]][[1]] (* Grau, corrected by Alonso del Arte, Jan 01 2014 *)

Crossrefs

Sequence in context: A346728 A197015 A239387 * A155920 A082124 A132721

Adjacent sequences: A226732 A226733 A226734 * A226736 A226737 A226738

Keyword

nonn,cons

Author

José María Grau Ribas, Jun 16 2013

Extensions

Offset and last term corrected by Rick L. Shepherd, Jan 01 2014

Status

approved