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%I #17 Nov 18 2015 05:00:06
%S 9,8,3,4,3,9,7,8,0,5,8,6,9,2,8,2,3,5,1,1,4,4,8,7,5,5,3,5,5,4,0,1,3,6,
%T 3,5,3,7,3,1,5,4,1,6,2,8,6,8,8,3,1,1,2,1,9,0,3,7,6,0,4,5,0,8,1,6,2,7,
%U 9,9,7,0,5,5,9,7,3,9,2,0,6,7,5,7,9,3,9,7,5,0,0,4,0,2,9,4,1,3,8,7,5,3,4,5,5
%N Decimal expansion of product_{n=2..infinity} (n^7-1)/(n^7+1).
%H J. Borwein et al., <a href="http://www.ams.org/mathscinet-getitem?mr=2051473">Experimentation in Mathematics</a>, 2004, section 1.2.
%H E. W. Weisstein, <a href="http://mathworld.wolfram.com/InfiniteProduct.html">Infinite Product</a>, MathWorld.
%e 0.9834397805869282351144875535540...
%t p = 2*Product[Gamma[2+(-1)^(k+k/7)], {k, 6}]/Product[Gamma[2-(-1)^(k+k/7)], {k, 6}]; RealDigits[Re[p], 10, 105][[1]] (* _Jean-François Alcover_, Feb 11 2013, updated Nov 18 2015 *)
%t RealDigits[Re[N[Product[(n^7 - 1)/(n^7 + 1), {n, 2, Infinity}], 110]]][[1]] (* _Bruno Berselli_, Apr 02 2013 *)
%Y Cf. A090986.
%K nonn,cons
%O 0,1
%A _R. J. Mathar_, Feb 01 2009
%E More terms from _Jean-François Alcover_, Feb 11 2013