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 A254445 #16 May 19 2022 08:07:23
%S A254445 2,0,7,1,1,2,1,3,2,9,9,6,7,8,2,3,1,6,9,5,7,1,5,7,2,9,9,2,6,8,3,5,2,6,
%T A254445 2,6,0,8,9,3,7,9,4,6,5,8,3,0,6,9,3,0,7,5,5,8,1,5,6,5,0,6,6,1,1,1,4,4,
%U A254445 5,1,2,2,6,6,1,2,2,6,2,9,3,7,3,2,7,1,2,5,0,0,2,2,2,9,5,0,5,2,8,5,5,6,4,6,7
%N A254445 Decimal expansion of Sum_{n>=0} 1/cosh(n).
%e A254445 2.071121329967823169571572992683526260893794658306930755815650661114451...
%p A254445 evalf(sum(1/cosh(n), n = 0..infinity), 120);
%t A254445 RealDigits[N[Re[Sum[1/Cosh[n],{n,0,Infinity}]],110],10,105][[1]]
%o A254445 (PARI) suminf(n=0, 1/cosh(n)) \\ _Michel Marcus_, Jan 30 2015
%Y A254445 Cf. A185393, A254446, A335415.
%K A254445 nonn,cons
%O A254445 1,1
%A A254445 _Vaclav Kotesovec_, Jan 30 2015