A259927 Decimal expansion of sum_{n>=1} (PolyGamma(2, n+1)/n^3) (negated).

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

Offset

0,1

Links

Table of n, a(n) for n=0..103.

Eric Weisstein's MathWorld, Polygamma Function.

Wikipedia, Polygamma Function.

Formula

Equals zeta(6) - zeta(3)^2.

Example

-0.427597736449185094199167149016067299281917915731035112289...

Mathematica

RealDigits[Zeta[6] - Zeta[3]^2, 10, 104] // First

Prog

(PARI) zeta(6) - zeta(3)^2 \\ Michel Marcus, Jul 09 2015

Crossrefs

Cf. A002117, A013664.

Sequence in context: A109857 A194075 A271479 * A002560 A124908 A260593

Adjacent sequences: A259924 A259925 A259926 * A259928 A259929 A259930

Keyword

nonn,cons,easy

Author

Jean-François Alcover, Jul 09 2015

Status

approved