A330646 Decimal expansion of the mean length of a line segment drawn by picking a random point on a unit length equilateral triangle and extending it in a random direction until it meets an edge.
3, 0, 2, 8, 4, 8, 3, 4, 9, 8, 0, 4, 0, 9, 7, 9, 3, 3, 3, 7, 5, 6, 9, 1, 3, 0, 3, 4, 9, 2, 5, 6, 4, 5, 7, 0, 8, 8, 4, 5, 9, 6, 9, 9, 0, 5, 7, 8, 2, 8, 5, 8, 1, 4, 5, 5, 8, 5, 0, 9, 2, 5, 3, 5, 1, 6, 3, 4, 0, 5, 1, 4, 4, 9, 4, 4, 5, 2, 5, 0, 2, 3, 3, 1, 0, 1, 1, 4, 7, 6, 0, 0, 2, 2, 6, 2, 0, 4, 3, 1, 8, 0, 3, 1, 7, 3, 8, 8, 6, 7
Offset: 0
Examples
0.302848349804097933375691303492564570884596990578285814558...
Links
- Muthu Veerappan Ramalingam, An Expected Value Problem III
Crossrefs
Cf. A093064.
Programs
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Mathematica
RealDigits[Sqrt[3] Log[3]/2/Pi, 10, 110][[1]]
Formula
Equals sqrt(3) * log(3) / (2 * Pi).
Equals (h_a/(3*Pi))*cosech^{-1}((1/2)*((b+c)/a-a/(b+c)))+(h_b/(3*Pi))*cosech^{-1}((1/2)*((c+a)/b-b/(c+a)))+(h_c/(3*Pi))*cosech^{-1}((1/2)*((a+b)/c-c/(a+b))) for an arbitrary triangle with sides a, b and c with corresponding altitudes h_a, h_b and h_c.