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 A232272 #26 Jan 03 2025 11:48:36
%S A232272 3,0,8,1,6,9,0,7,1,1,1,5,9,8,4,9,3,5,7,8,6,9,9,9,6,0,8,0,3,4,0,5,3,0,
%T A232272 9,8,5,8,9,6,3,7,0,2,9,2,6,3,1,6,9,3,1,3,5,1,3,6,6,2,3,4,3,9,0,1,6,8,
%U A232272 2,9,0,0,4,5,1,3,7,0,5,3,3,9,6,8,9
%N A232272 Decimal expansion of arctan(1/Pi).
%D A232272 Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 35, page 338.
%F A232272 Equals A019669 - A232273.
%F A232272 Equals Sum_{i>=0} (-1)^k/((1+2*k)*Pi^(1+2*k)).
%F A232272 From _Wolfe Padawer_, Feb 16 2023: (Start)
%F A232272 Equals arccot(Pi).
%F A232272 Equals arcsin(1/sqrt(Pi^2 + 1)).
%F A232272 Equals arccos(1/sqrt(1 + 1/Pi^2)). (End)
%e A232272 0.30816907111598493578699960803405309858963702926316931351366234390168...
%t A232272 RealDigits[ArcTan[1/Pi], 10, 90][[1]]
%o A232272 (PARI) atan(1/Pi) \\ _Charles R Greathouse IV_, Nov 26 2024
%Y A232272 Cf. A019669, A049541, A232247, A232273.
%K A232272 nonn,cons
%O A232272 0,1
%A A232272 _Bruno Berselli_, Nov 22 2013