%I #15 Feb 11 2025 14:21:20
%S 3,1,1,5,2,9,3,0,7,5,3,8,8,4,0,1,6,6,0,0,4,4,6,3,5,9,0,2,9,5,5,1,2,6,
%T 6,3,2,5,2,8,9,7,7,9,6,2,7,0,3,6,2,9,3,7,4,3,6,7,8,1,8,2,2,2,5,6,3,8,
%U 9,7,2,4,8,3,9,9,6,6,2,4,6,7,0,4,4,1,3,4,7,3,6,5,1,3,0,2,1,3,8,8,8,8,2,4,5
%N Decimal expansion of 14*sin(Pi/14).
%C Decimal expansion of the ratio of the perimeter of a regular 7-gon (heptagon) to its diameter (largest diagonal).
%H G. C. Greubel, <a href="/A280533/b280533.txt">Table of n, a(n) for n = 1..10000</a>
%H <a href="/index/Al#algebraic_03">Index entries for algebraic numbers, degree 3</a>.
%F Equals 14*A232736.
%e 3.115293075388401660044635902955126632528977962703629374367818222563897248...
%t RealDigits[14*Sin[Pi/14], 10, 129][[1]] (* _G. C. Greubel_, Sep 20 2022 *)
%o (PARI) 14*sin(Pi/14)
%o (SageMath) numerical_approx(14*sin(pi/14), digits=127) # _G. C. Greubel_, Sep 20 2022
%Y Cf. For other n-gons: A010466 (n=4), 10*A019827 (n=5, 10), A280585 (n=8), A280633 (n=9), A280725 (n=11), A280819 (n=12).
%Y Cf. A232736.
%K nonn,cons,changed
%O 1,1
%A _Rick L. Shepherd_, Jan 04 2017