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A144665
Decimal expansion of product_{n=2..infinity} (n^6-1)/(n^6+1).
2
9, 6, 5, 9, 0, 6, 0, 8, 5, 7, 6, 2, 1, 5, 9, 2, 1, 2, 1, 5, 7, 0, 6, 2, 3, 7, 0, 5, 5, 0, 4, 5, 2, 0, 4, 0, 8, 5, 7, 2, 6, 8, 1, 3, 3, 6, 5, 0, 9, 7, 4, 5, 8, 9, 2, 5, 6, 2, 9, 6, 6, 3, 9, 4, 9, 2, 7, 3, 7, 7, 0, 2, 4, 9, 0, 0, 7, 5, 7, 3, 0, 9, 3, 2, 7, 1, 1, 1, 0, 7, 7, 7, 1, 6, 8, 8, 1, 1, 1, 4, 7, 4, 8, 5, 0
OFFSET
0,1
LINKS
J. Borwein et al., Experimentation in Mathematics, 2004, section 1.2.
E. W. Weisstein, Infinite Product, MathWorld.
FORMULA
c=(Pi/3)*(cosh(sqrt(3)*Pi)+1)/(sinh(Pi)*(cosh(Pi)-cos(sqrt(3)*Pi))).
EXAMPLE
0.96590608576215921215...
MATHEMATICA
RealDigits[ -((Pi*(1 + Cosh[Sqrt[3]*Pi])*Csch[Pi])/(3*(Cos[Sqrt[3]*Pi] - Cosh[Pi]))), 10, 105] // First (* Jean-François Alcover, Feb 11 2013 *)
PROG
(PARI) Pi*(cosh(sqrt(3)*Pi)+1)/sinh(Pi)/(cosh(Pi)-cos(sqrt(3)*Pi))/3 \\ - M. F. Hasler, Feb 23 2013
CROSSREFS
Cf. A090986.
Sequence in context: A247040 A019942 A102047 * A019884 A103814 A245770
KEYWORD
nonn,cons
AUTHOR
R. J. Mathar, Feb 01 2009
STATUS
approved