A091473 - OEIS

%I #18 Jan 04 2023 11:48:51

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

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

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

%N Integral_{x>=0} (cos(2x) * Product_{n>=1} cos(x/n)) dx.

%C First differs from Pi/8 (A019675) in the 42nd place.

%H D. H. Bailey, J. M. Borwein, V. Kapoor and E. Weisstein, <a href="https://www.davidhbailey.com/dhbpapers/tenproblems.pdf">Ten Problems in Experimental Mathematics</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DefiniteIntegral.html">Definite Integral</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/InfiniteCosineProductIntegral.html">Infinite Cosine Product Integral</a>

%e 0.3926990816987...

%Y Cf. A091494, A019675, A190573, A221208.

%K nonn,cons

%O 0,1

%A _Eric W. Weisstein_, Jan 13 2004