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.

A058655 Decimal expansion of area under the curve 1/Gamma(x) from zero to infinity.

Original entry on oeis.org

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

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Author

Robert G. Wilson v, Jan 05 2001

Keywords

Comments

Referred to as the Fransén-Robinson constant.
Named Fransén-Robinson constant after Herman P. Robinson, who calculated its value to 36 decimal digits (Fransén, 1979), and Arne Fransén, who calculated its value to 80 decimal digits (1981). - Amiram Eldar, Aug 13 2020

Examples

			2.807770242028519365221501186557772932308085920930198291220054809597100...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003. See pp. 262-264.

Crossrefs

Cf. A046943 (continued fraction).

Programs

  • Mathematica
    RealDigits[ NIntegrate[ 1 / Gamma[ x ], {x, 0, Infinity}, AccuracyGoal -> 72, WorkingPrecision -> 90 ] ][ [ 1 ] ]
  • PARI
    intnum(x=0,[[1],1],1/gamma(x)) \\ Bill Allombert, May 18 2015

Formula

Equals e + Integral_{x=0..oo} exp(-x)/(Pi^2 + log(x)^2) dx. - Amiram Eldar, Aug 13 2020

Extensions

More terms from Philip Sung (philip_sung(AT)hotmail.com), Jan 22 2002