A120670 Decimal expansion of 180*arccos(1-8/(Pi^2))/Pi.

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

Offset: 2

Author

Rick L. Shepherd, Jun 22 2006

Keywords

• cons
• nonn

Comments

For a circle with radius r, the measurement in degrees of the central angle with endpoints on the circle that are r*4/Pi apart: The average central angle (<= 180 degrees) formed using two randomly chosen points on a circle. The average arc length between such endpoints is r*A120669 corresponding to the average chord length r*A088538; so for the unit circle arc length is A120669 and chord length is A088538.

Examples

			79.0804474956203908253980311180...
		

Crossrefs

Cf. A088538, A120669 (same in radians), A120671 (A120670/360).

Programs

Mathematica

RealDigits[180 ArcCos[1-8/Pi^2]/Pi,10,120][[1]] (* Harvey P. Dale, Feb 17 2023 *)

PARI

180*acos(1-8/Pi^2)/Pi

Formula

Equals 180*A120669/Pi = 360*A120671.