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 A197684 #15 Oct 01 2022 00:46:43
%S A197684 1,1,9,1,5,2,2,8,3,0,2,9,7,5,0,8,5,4,6,5,5,9,1,0,6,3,4,7,1,1,7,3,0,5,
%T A197684 0,1,0,0,2,9,3,7,1,5,1,6,8,6,7,2,8,7,4,1,2,1,5,2,9,7,8,1,8,9,2,6,2,6,
%U A197684 3,4,1,3,4,5,9,2,6,2,5,8,1,1,1,5,3,7,0,0,8,2,5,6,6,3,3,8,0,6,4
%N A197684 Decimal expansion of Pi^2/(2 + 2*Pi).
%C A197684 Least x > 0 such that sin(bx) = cos(cx) (and also sin(cx) = cos(bx)), where b=1 and c=1/Pi; see the Mathematica program for a graph and A197682 for a discussion and guide to related sequences.
%H A197684 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%e A197684 1.191522830297508546559106347117305010029371...
%t A197684 b = 1; c = 1/Pi;
%t A197684 t = x /. FindRoot[Sin[b*x] == Cos[c*x], {x, 1.1, 1.2}]
%t A197684 N[Pi/(2*b + 2*c), 110]
%t A197684 RealDigits[%] (* A197684 *)
%t A197684 Simplify[Pi/(2*b + 2*c)]
%t A197684 Plot[{Sin[b*x], Cos[c*x]}, {x, 0, Pi/2}]
%Y A197684 Cf. A197682.
%K A197684 nonn,cons
%O A197684 1,3
%A A197684 _Clark Kimberling_, Oct 17 2011
%E A197684 Offset changed by _Georg Fischer_, Jul 29 2021