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 A246856 #11 Jan 17 2020 16:12:04 %S A246856 4,8,5,6,0,5,5,3,2,0,9,3,1,6,6,2,0,3,8,6,2,6,4,3,5,3,4,8,9,0,5,2,9,3, %T A246856 9,8,5,5,1,9,5,3,7,8,3,1,0,2,0,8,8,0,2,5,8,3,8,3,4,6,2,1,2,4,3,6,0,6, %U A246856 2,2,7,9,0,2,3,6,5,5,0,5,9,2,8,0,6,9,8,2,6,2,7,2,6,5,7,8,9,6,2,4,2,9 %N A246856 Decimal expansion of 'alpha', the threshold angle associated with the best constant in [a variation of] Hardy's inequality for a domain defined as a non-convex plane sector of angle alpha. %H A246856 Steven R. Finch, <a href="http://arxiv.org/abs/2001.00578">Errata and Addenda to Mathematical Constants</a>, p. 30. %F A246856 alpha = Pi + 4*arctan(4*Gamma(3/4)^2/Gamma(1/4)^2). %e A246856 4.85605532093166203862643534890529398551953783102088... %t A246856 alpha = Pi + 4*ArcTan[4*Gamma[3/4]^2/Gamma[1/4]^2]; RealDigits[alpha, 10, 102] // First %o A246856 (PARI) Pi + 4*atan(4*gamma(3/4)^2/gamma(1/4)^2) \\ _Michel Marcus_, Sep 05 2014 %Y A246856 Cf. A068465, A068466. %K A246856 nonn,cons,easy %O A246856 1,1 %A A246856 _Jean-François Alcover_, Sep 05 2014