A248895 Decimal expansion of Sum_{i >= 1} 1/(4*i^2-1)^3.

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

Offset

0,2

Links

Table of n, a(n) for n=0..86.

Xavier Gourdon and Pascal Sebah, Collection of series for Pi (see paragraph 7).

Formula

Equals 1/2 - 3*(Pi/8)^2.

Example

0.0373622936989363147421332343808054155321703402855879393868742479896853989...

Mathematica

Join[{0}, RealDigits[1/2 - 3 (Pi/8)^2, 10, 100][[1]]]

Crossrefs

Cf. A123092: Sum_{i >= 1} 1/(4*i^2-1)^2.

Cf. A248896: Sum_{i >= 1} 1/(4*i^2-1)^4.

Sequence in context: A001265 A060443 A020810 * A021732 A329341 A244191

Adjacent sequences: A248892 A248893 A248894 * A248896 A248897 A248898

Keyword

nonn,cons

Author

Bruno Berselli, Mar 06 2015

Status

approved