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 A195781 #17 Nov 20 2024 23:45:39 %S A195781 1,4,4,6,4,4,1,3,3,2,2,4,8,1,3,5,1,8,4,1,9,9,9,6,6,8,4,2,4,7,5,8,8,0, %T A195781 4,1,6,5,2,5,4,1,4,5,0,7,9,1,7,7,4,8,8,2,0,5,7,2,3,5,8,1,7,7,0,3,8,1, %U A195781 8,5,9,3,5,7,1,5,5,3,7,7,4,0,6,9,0,3,0,6,8,1,8,3,5,7,7,0,5,2,0,3 %N A195781 Decimal expansion of arctan(8). %H A195781 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a> %F A195781 Equals arccot(1/8) = arcsin(8/sqrt(65)) = arccos(1/sqrt(65)). - _Amiram Eldar_, May 24 2021 %F A195781 Equals arctan(1) + arctan(1/2) + arctan(1/5). - _Amiram Eldar_, Jan 11 2022 %e A195781 arctan(8) = 1.4464413322481351841999668424758804165254145079... %t A195781 r = 8; %t A195781 N[ArcTan[r], 100] %t A195781 RealDigits[%][[1]] %o A195781 (PARI) atan(8) \\ _Charles R Greathouse IV_, Nov 20 2024 %Y A195781 Cf. A195782, A195783, A195784. %K A195781 nonn,cons %O A195781 1,2 %A A195781 _Clark Kimberling_, Sep 24 2011