A144667 - OEIS

A144667

Decimal expansion of product_{n=2..infinity} (n^8-1)/(n^8+1).

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

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OFFSET

0,1

LINKS

Table of n, a(n) for n=0..104.

J. Borwein et al., Experimentation in Mathematics, 2004, section 1.2.

E. W. Weisstein, Infinite Product, MathWorld.

FORMULA

Equals 2*A175619/A334411. - Vaclav Kotesovec, Apr 27 2020

EXAMPLE

0.9918784076582948169664...

MATHEMATICA

RealDigits[-1/4*Pi*Csc[(-1)^(1/8)*Pi]*Csc[(-1)^(3/8)*Pi]*Csc[(-1)^(5/8)*Pi] * Csc[(-1)^(7/8)*Pi]*Sin[(-1)^(1/4)*Pi]*Sin[(-1)^(3/4)*Pi]*Sinh[Pi] // Re, 10, 105] // First (* Jean-François Alcover, Feb 11 2013 *)

CROSSREFS

Cf. A090986.

Sequence in context: A266555 A343367 A145280 * A118428 A166925 A178164

Adjacent sequences: A144664 A144665 A144666 * A144668 A144669 A144670

KEYWORD

nonn,cons

AUTHOR

R. J. Mathar, Feb 01 2009

EXTENSIONS

More terms from Jean-François Alcover, Feb 11 2013

STATUS

approved