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 A308715 #8 Jun 20 2019 02:56:53
%S A308715 2,5,0,9,1,7,8,4,7,8,6,5,8,0,5,6,7,8,2,0,0,9,9,9,5,6,4,3,2,6,9,4,0,5,
%T A308715 9,4,8,2,1,2,0,2,4,3,5,8,1,4,8,1,5,2,2,7,4,0,4,7,9,7,5,6,8,6,1,4,8,9,
%U A308715 8,5,8,9,1,0,8,8,5,3,2,1,3,8,2,6,8,6,5,2,5,2,2,2,2,4,6,5,4,6,9,4,9,9,8,9,0,1,9,9,8,0,2,1,4,6,7,0,7,5,5,3
%N A308715 Decimal expansion of cosh(Pi/2).
%F A308715 Equals Product_{k>=1} (1 + 1/(2*k - 1)^2).
%F A308715 Equals Product_{k>=0} (1 + 1/A016754(k)).
%e A308715 2.50917847865805678200999564326940594821202435...
%t A308715 RealDigits[Cosh[Pi/2], 10, 120][[1]]
%o A308715 (PARI) cosh(Pi/2) \\ _Michel Marcus_, Jun 20 2019
%Y A308715 Cf. A003881, A016754, A156648, A308716.
%K A308715 nonn,cons
%O A308715 1,1
%A A308715 _Ilya Gutkovskiy_, Jun 19 2019