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 A377405 #18 Nov 01 2024 03:52:40
%S A377405 5,3,4,4,7,9,6,6,6,0,5,7,7,9,7,5,5,6,7,1,2,5,9,2,1,8,6,2,5,3,4,4,1,3,
%T A377405 1,9,9,5,0,7,2,5,4,6,2,6,3,3,2,6,2,2,9,3,0,0,3,3,3,1,6,2,8,1,8,9,8,1,
%U A377405 0,5,7,4,8,3,9,5,3,7,4,5,6,6,1,3,9,0,1,9,3,8,9,7,1,3,4,8,3,3,0,7
%N A377405 Decimal expansion of Pi*csc(Pi/5).
%D A377405 Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.5.4, p. 33.
%H A377405 Michael I. Shamos, <a href="http://euro.ecom.cmu.edu/people/faculty/mshamos/cat.pdf">A catalog of the real numbers</a>, (2007). See p. 360.
%H A377405 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%F A377405 Equals Gamma(1/5)*Gamma(4/5) = 2*Pi*sqrt(5)*sqrt(2+phi)/5 (see Finch).
%F A377405 Equals Integral_{x=0..oo} log(1 + x^(-5)) dx (see Shamos).
%F A377405 Equals sqrt(2*(1 + 1/sqrt(5)))*Pi.
%F A377405 Equals 10 * Sum_{n>=1} (-1)^(n+1)/A345019(n). - _Amiram Eldar_, Oct 27 2024
%F A377405 Equals 5*A352324. - _Hugo Pfoertner_, Oct 28 2024
%e A377405 5.344796660577975567125921862534413199507254626...
%t A377405 RealDigits[Pi*Csc[Pi/5],10,100][[1]]
%Y A377405 Cf. A000796, A001622, A002163, A010476, A019692, A175380, A345019, A340722, A352324.
%K A377405 nonn,cons
%O A377405 1,1
%A A377405 _Stefano Spezia_, Oct 27 2024