A371801 Decimal expansion of Sum_{k>=0} (-1)^k / (k^2 + 2).

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

Offset

0,1

Links

Table of n, a(n) for n=0..85.

Formula

Equals (1/4)*(1 + sqrt(2)*Pi*csch(Pi*sqrt(2))).

Example

0.2761321665442393236159323372823389370644098...

Mathematica

s = N[Sum[(-1)^k/(k^2 + 2), {k, 0, Infinity}], 120]
First[RealDigits[s]]

Crossrefs

Cf. A329083.

Sequence in context: A070524 A259830 A259235 * A264692 A021366 A334366

Adjacent sequences: A371798 A371799 A371800 * A371802 A371803 A371804

Keyword

nonn,cons

Author

Clark Kimberling, Apr 24 2024

Status

approved