This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A330865 #11 Apr 28 2020 17:08:43
%S A330865 7,9,8,6,9,6,3,1,5,9,5,6,4,6,3,0,8,4,8,6,3,8,0,6,7,0,4,2,2,1,0,9,6,1,
%T A330865 3,8,6,9,1,4,9,2,8,7,4,1,8,5,1,2,9,1,2,3,4,8,3,7,2,6,6,4,0,6,4,5,9,0,
%U A330865 2,4,3,1,1,2,9,6,8,6,5,4,3,0,6,7,6,6,4,1,0,6,5,9,8,7,3,9,6,2,3,2,2,2,5,7,1,0,1,5,8,5
%N A330865 Decimal expansion of cosh(Pi/2)/Pi.
%F A330865 Equals Sum_{k>=0} Pi^(2*k-1)/(4^k*(2*k)!).
%F A330865 Equals Product_{k>=2} (1 - (-1)^k/k^2).
%F A330865 Equals (i^(-i) + i^i)/(2*Pi), where i is the imaginary unit.
%e A330865 (1 - 1/2^2) * (1 + 1/3^2) * (1 - 1/4^2) * (1 + 1/5^2) * (1 - 1/6^2) * ... = (e^(Pi/2) + e^(-Pi/2))/(2*Pi) = 0.7986963159564630848638067...
%t A330865 RealDigits[Cosh[Pi/2]/Pi, 10, 110] [[1]]
%o A330865 (PARI) cosh(Pi/2)/Pi \\ _Michel Marcus_, Apr 28 2020
%Y A330865 Cf. A042972, A049006, A049541, A156648, A175615, A308715, A308716, A308718, A323982, A330864, A334402.
%K A330865 nonn,cons
%O A330865 0,1
%A A330865 _Ilya Gutkovskiy_, Apr 28 2020