A374814 Decimal expansion of Sum_{k>=0} cos(3k*Pi/5)/2^k.

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

Offset: 0

Author

Clark Kimberling, Jul 20 2024

Keywords

• nonn
• cons

Examples

			0.74053618488639231412602177244573...
		

Crossrefs

Cf. A373021 (includes guide to related sequences).

Programs

Mathematica

{b, m, h} = {2, 5, 3}; s = Sum[Cos[ h  k  Pi/m]/b^k, {k, 0, Infinity}]
d = N[s, 100]
First[RealDigits[d], 100]

Formula

Equals (23 - 3*sqrt(5))/22.

Equals Sum_{k>=0} cos(7 k*Pi/5)/2^k.

Minimal polynomial: 11 - 23 x + 11 x^2.