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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.

User: Robert M. Ziff

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Robert M. Ziff has authored 1 sequences.

A160439 Decimal expansion of a constant that appears in flux/diffusion problems with trapping surfaces.

Original entry on oeis.org

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

Author

Robert M. Ziff, May 13 2009

Keywords

Comments

The constant appears as a correction in effective radii of flux problems of particles undergoing certain random walks in one or three dimensions.
Also related to correction term to the asymptotics of sums of random numbers uniformly distributed on an interval (see Coffman et al., who also present a double-sum formula.)

Examples

			0.29795219028004776416465987228031204613834651480951717550256...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 5.9, p. 327.

Programs

  • Maple
    evalf(-1/Pi * Int(log(6/x^2*(1-sin(x)/x))/x^2, x=0..infinity),20); # Vaclav Kotesovec, Mar 17 2015
  • Mathematica
    For[i = 0; s = 0, i < 100, i++, s = s + -(1/Pi)NIntegrate[Log[(1 - Sin[x]/ x)/(x^2/6)]/x^2, {x, 2 i Pi, 2 (i + 1) Pi}, WorkingPrecision -> 100]; Print[s]]
    RealDigits[-1/Pi * Integrate[Log[(6/x^2) * (1 - Sin[x]/x)]/x^2, {x, 0, Infinity}], 10, 100][[1]] (* Alonso del Arte, Mar 18 2015 *)

Formula

Equals (-1/Pi) * Integral_{x=0..oo} log( (6/x^2)*(1-sin(x)/x) ) / x^2 dx.

Extensions

Definition condensed by R. J. Mathar, May 30 2009
Corrected decimal places 39-46 and added more decimals by Vaclav Kotesovec, Mar 18 2015
More terms from Vaclav Kotesovec, Dec 07 2016