A373022 Decimal expansion of Sum_{k>=0} sin(2*k*Pi/5)/2^k.

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

Offset: 0

Author

Clark Kimberling, Jul 20 2024

Keywords

• nonn
• cons

Examples

			0.505352652816194920203386273737665...
		

Crossrefs

Cf. A373021 (includes guide to related sequences).

Programs

Mathematica

{b, m, h} = {2, 5, 2}; s = Sum[Sin[ h k Pi/m]/b^k, {k, 0, Infinity}]
d = N[s, 100]
First[RealDigits[d], 100]

Formula

Equals sqrt(2*(5 + sqrt(5)))/(12 - 2*sqrt(5)).

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

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