A178818 - OEIS

%I #17 Sep 08 2022 08:45:54

%S 2,0,7,6,5,2,1,3,9,6,5,7,2,3,3,6,5,6,7,1,6,3,5,3,8,8,6,1,4,8,5,8,4,0,

%T 3,3,0,7,0,5,7,2,0,2,0,6,6,2,5,9,6,8,5,2,4,0,8,3,4,1,7,3,7,6,8,6,3,0,

%U 2,8,4,8,7,0,6,4,5,9,7,7,1,7,4,6,4,4,1,7,5,5,1,5,9,7,6,0,6,2,2,5,3,5,4,8,8

%N Decimal expansion of the diameter of the regular 7-gon (heptagon) of edge length 1.

%H G. C. Greubel, <a href="/A178818/b178818.txt">Table of n, a(n) for n = 1..10000</a>

%F Digits of cot(Pi/7).

%e 2.07652139657233656716353886148584033070572020662596852408341737686302...

%p evalf[120](cot(Pi/7)); # _Muniru A Asiru_, Jan 22 2019

%t RealDigits[Cot[Pi/7],10, 100][[1]]

%o (PARI) default(realprecision, 100); cotan(Pi/7) \\ _G. C. Greubel_, Jan 22 2019

%o (Magma) SetDefaultRealField(RealField(100)); R:=RealField(); Cot(Pi(R)/7); // _G. C. Greubel_, Jan 22 2019

%o (Sage) numerical_approx(cot(pi/7), digits=100) # _G. C. Greubel_, Jan 22 2019

%Y Cf. A090488, A102771, A104956, A120011, A178809, A178816, A178817.

%K nonn,easy,cons

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Jun 16 2010