%I #18 Apr 01 2024 07:00:46
%S 9,8,5,3,5,2,0,8,4,3,8,7,2,2,0,6,2,3,3,0,3,4,9,1,1,1,3,7,9,0,6,4,8,6,
%T 7,7,1,2,1,5,9,2,5,6,3,5,6,6,8,2,8,6,3,8,6,5,3,7,8,4,8,7,8,8,8,5,1,8,
%U 5,1,4,1,2,1,3,8,2,5,6,5,2,8,6,7,9,1,3,7,8,0,8,0,6,1,5,7,8,7,5,0
%N Decimal expansion of Product_{k>=1} (1 - 1/(2*k+1)^4).
%F Equals (1/8) * Pi * cosh(Pi/2).
%e 0.98535208438722062330349111379064867712159256...
%t RealDigits[(1/8) Pi Cosh[Pi/2], 10, 100][[1]]
%Y Cf. A003881, A175615, A258870, A369880, A371465.
%K nonn,cons
%O 0,1
%A _Ilya Gutkovskiy_, Mar 31 2024