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.

A242616 Decimal expansion of lim_(n->infinity) ((Sum_(k=1..n) 1/sqrt(k)) - (Integral_{x=1..n} 1/sqrt(x))), a generalized Euler constant which evaluates to zeta(1/2) + 2.

Original entry on oeis.org

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

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Author

Jean-François Alcover, May 19 2014

Keywords

Comments

Sometimes called Ioachimescu's constant, after the Romanian mathematician and engineer Andrei Gheorghe Ioachimescu (1868-1943). - Amiram Eldar, Apr 02 2022

Examples

			0.53964549119041318711050084748470198753277...
		

References

  • Vasile Berinde and Eugen Păltănea, Gazeta Matematică - A Bridge Over Three Centuries, Romanian Mathematical Society, 2004, pp. 113-114.
  • Steven R. Finch, Mathematical Constants, Cambridge, 2003, Section 1.5.3, p. 32.
  • A. G. Ioachimescu, Problem 16, Gazeta Matematică, Vol. 1, No. 2 (1895), p. 39.

Crossrefs

Programs

  • Magma
    SetDefaultRealField(RealField(100)); L:=RiemannZeta(); 2 + Evaluate(L, 1/2) // G. C. Greubel, Sep 04 2018
  • Mathematica
    RealDigits[Zeta[1/2] + 2, 10, 100] // First
  • PARI
    default(realprecision, 100); zeta(1/2)+2 \\ G. C. Greubel, Sep 04 2018
    

Formula

Equals zeta(1/2) + 2.