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 A232715 #17 Oct 01 2022 00:13:59 %S A232715 4,2,4,4,1,3,1,8,1,5,7,8,3,8,7,5,6,2,0,5,0,3,5,6,7,0,2,3,2,6,7,0,4,9, %T A232715 6,5,4,2,5,2,2,5,7,2,1,9,7,4,5,5,0,5,2,9,9,9,3,7,7,9,5,8,4,1,5,7,0,5, %U A232715 8,1,2,7,0,2,4,6,0,4,0,9,3,5,7,3,6 %N A232715 Decimal expansion of the ratio of the area of a parbelos to the area of its associated arbelos: 4/(3*Pi). %C A232715 Also distance from the diameter of unit semicircle to its centroid. - _Franck Maminirina Ramaharo_, Oct 22 2018 %H A232715 J. Sondow, <a href="http://arxiv.org/abs/1210.2279">The parbelos, a parabolic analog of the arbelos</a>, arXiv 2012, Amer. Math. Monthly 120 (2013) 929-935. %H A232715 E. Tsukerman, <a href="http://arxiv.org/abs/1210.5580">Solution of Sondow's problem: a synthetic proof of the tangency property of the parbelos</a>, arXiv 2012. %H A232715 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a> %e A232715 0.424413181578387562050356702326704965425225721974550529993779... %t A232715 RealDigits[4/(3 Pi),10,100] %o A232715 (PARI) 4/Pi/3 \\ _Charles R Greathouse IV_, Oct 01 2022 %Y A232715 Reciprocal of A177870. Ratio of lengths of boundaries is A232716. %K A232715 nonn,cons,easy %O A232715 0,1 %A A232715 _Jonathan Sondow_, Nov 28 2013