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 A244854 #28 Dec 10 2022 18:52:30
%S A244854 3,0,8,4,2,5,1,3,7,5,3,4,0,4,2,4,5,6,8,3,8,5,7,7,8,4,3,7,4,6,1,2,9,7,
%T A244854 2,2,9,7,8,5,5,3,1,0,6,4,7,6,2,7,4,7,0,7,0,7,5,4,1,7,1,6,8,0,0,6,8,7,
%U A244854 6,4,0,0,7,0,0,6,0,0,1,6,3,8,4,3,8,0,5
%N A244854 Decimal expansion of Pi^2/32.
%C A244854 Probability that a point selected uniformly at random from the unit 4-cube is in the unit 4-sphere.
%C A244854 Let S(n) = 1 - 1/3 + 1/5 - ... + ((-1)^(n-1))/(2n-1). Then Sum{n >=1} ((-1)^(n-1))*S(n) /(2n+1) = Pi^2 /32. The convergence is very slow. - _Michel Lagneau_, Feb 27 2015
%H A244854 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%F A244854 Equals Integral_{0..infinity} x^2*BesselK(0, x)^2 dx. - _Jean-François Alcover_, Apr 15 2015
%F A244854 Equals Integral_{x=0..1} arctan(x)/(1+x^2) dx. - _Amiram Eldar_, Aug 09 2020
%F A244854 Equals Integral_{x=0..1} Integral_{y=0..1} Integral_{z=0..1} (1 + x^2 + y^2 + z^2)^(-2). - _Peter Luschny_, Dec 10 2022
%e A244854 Choose -1 <= w, x, y, z <= 1 uniformly at random. Then this constant is the probability that w^2 + x^2 + y^2 + z^2 <= 1.
%p A244854 Digits:=100; evalf(Pi^2/32); # _Wesley Ivan Hurt_, Feb 27 2015
%t A244854 RealDigits[Pi^2/32,10,120][[1]] (* _Harvey P. Dale_, Jul 13 2014 *)
%o A244854 (PARI) Pi^2/32
%Y A244854 Cf. A003881 (2-dimensional analog), A019673 (3-dimensional analog).
%K A244854 nonn,cons
%O A244854 0,1
%A A244854 _Charles R Greathouse IV_, Jul 07 2014