cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A073012 Decimal expansion of Robbins constant.

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Aug 03 2002

Keywords

Comments

The average distance between two points chosen at random inside a unit cube.
This constant was named after the American mathematician David Peter Robbins (1942 - 2003). - Amiram Eldar, Aug 25 2020

Examples

			0.66170718226717623515583113324841358174640013579095...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, p. 479.
  • Steven R. Finch, Mathematical Constants II, Cambridge University Press, 2018, p. 693.
  • Francois Le Lionnais, Les nombres remarquables, Paris: Hermann, 1983. See p. 30.

Crossrefs

Programs

  • Mathematica
    RealDigits[ N[4/105 + 17/105*Sqrt[2] - 2/35*Sqrt[3] + 1/5*Log[1 + Sqrt[2]] + 2/5*Log[2 + Sqrt[3]] - 1/15*Pi, 110]] [[1]]
  • PARI
    (4 + 17*sqrt(2) - 6*sqrt(3) + 21*log(1 + sqrt(2)) + 42*log(2 + sqrt(3)) - 7*Pi)/105 \\ G. C. Greubel, Jan 11 2017

Formula

4/105 + (17/105) * sqrt(2) - (2/35) * sqrt(3) + (1/5) * log(1+sqrt(2)) + (2/5) * log(2+sqrt(3)) - (1/15) * Pi. - Eric W. Weisstein, Mar 02 2005