A373022 - OEIS

%I #4 Jul 22 2024 15:27:48

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

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

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

%N Decimal expansion of Sum_{k>=0} sin(2k*Pi/5)/2^k.

%F Equals sqrt((5 + sqrt(5)]/(12 - 2 sqrt(5)).

%F Equals (-1)*Sum_{k>=0} sin(8 k*Pi/5)/2^k.

%F Minimal polynomial: 5 - 265 x^2 + 961 x^4.

%e 0.505352652816194920203386273737665...

%t {b, m, h} = {2, 5, 2}; s = Sum[Sin[ h k Pi/m]/b^k, {k, 0, Infinity}]

%t d = N[s, 100]

%t First[RealDigits[d], 100]

%Y Cf. A373021 (includes guide to related sequences).

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Jul 20 2024