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 A179377 #13 Feb 16 2025 08:33:12
%S A179377 2,8,9,4,9,4,1,8,3,0,2,7,8,6,2,6,5,0,0,9,4,3,6,0,7,5,7,3,0,5,1,5,4,7,
%T A179377 3,2,3,9,3,8,1,0,4,5,1,9,9,8,9,6,1,2,7,0,2,0,7,4,6,5,2,2,6,1,4,4,0,8,
%U A179377 9,1,2,1,2,6,3,3,3,0,8,8,7,5,3,1,9,6,4,2,2,7,9,3,9,5,8,6,0,7,1,5,6,2,3,4,7
%N A179377 Decimal expansion of the ratio of the height of the triangle corresponding to a circular segment with area r^2 of a circle with radius r to r itself.
%C A179377 In other words, the triangle height is A179377*r. The segment height ("cap height" in MathWorld link) is A179376*r. The chord length is A179375*r. The arc length of the circular segment/sector is r*A179373. The area of the circular segment, r^2, is 1/Pi (A049541) times the area of the circle. The area of the sector is (r^2)*(A179373/2) = (r^2)*(1 + A179378). See references and cross-references for other relationships.
%D A179377 S. Selby, editor, CRC Basic Mathematical Tables, CRC Press, 1970, p. 7.
%H A179377 G. C. Greubel, <a href="/A179377/b179377.txt">Table of n, a(n) for n = 0..10000</a>
%H A179377 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CircularSegment.html">Circular Segment</a>.
%F A179377 Equals cos(A179373/2) = 1 - A179376.
%e A179377 .2894941830278626500943607573051547323938104519989612702074652261440891212633...
%t A179377 RealDigits[ Cos[x/2] /. FindRoot[x - Sin[x] - 2, {x, 1}, WorkingPrecision -> 106]][[1]] (* _Jean-François Alcover_, Oct 30 2012 *)
%o A179377 (PARI) cos(solve(x=0, Pi, x-sin(x)-2)/2)
%Y A179377 Cf. A179373 (central angle, radians), A179374 (central angle, degrees), A179375 (for chord length), A179376 (for "cap height", height of segment), A179378 (for triangle area), A049541.
%K A179377 cons,nonn
%O A179377 0,1
%A A179377 _Rick L. Shepherd_, Jul 11 2010