A388540 Decimal expansion of Sum_{k>=1} 1/(9*k-8)^3.

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

Offset

1,5

Links

Table of n, a(n) for n=1..100.

Michael I. Shamos, Shamos's Catalog of the Real Numbers, 2011, p. 29.

Formula

Equals (-1/1458) * PolyGamma(2, 1/9).

Example

1.0012429781201955375371963846399182315900879403566511...

Mathematica

First[RealDigits[-1/1458 * PolyGamma[2, 1/9], 10, 100]]

Crossrefs

Sequence in context: A058942 A365638 A196759 * A303165 A188813 A324958

Adjacent sequences: A388537 A388538 A388539 * A388541 A388542 A388543

Keyword

nonn,cons

Author

Jason Bard, Oct 16 2025

Status

approved