A145423 Decimal expansion of Sum_{n>=1} (-1)^(n-1)/(n^2-1/4)^2.

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

Offset

1,2

References

Alexander Apelblat, Tables of Integrals and Series, Harri Deutsch, (1996), 4.1.18

Links

G. C. Greubel, Table of n, a(n) for n = 1..5000

Formula

Equals 8 - A019692 = 8 - 2*Pi.

Example

1.7168146928204135...

Maple

evalf(8-2*Pi) ;

Mathematica

RealDigits[8 - 2*Pi, 10, 50][[1]] (* G. C. Greubel, Jun 26 2017 *)

Prog

(PARI) 8 - 2*Pi \\ G. C. Greubel, Jun 26 2017

Crossrefs

Sequence in context: A358187 A255888 A060625 * A019796 A309600 A190264

Adjacent sequences: A145420 A145421 A145422 * A145424 A145425 A145426

Keyword

cons,easy,nonn

Author

R. J. Mathar, Feb 08 2009

Status

approved