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.

A019706 Decimal expansion of sqrt(Pi)/4.

Original entry on oeis.org

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

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Examples

			0.44311346272637900682454187083528629569938736403059678...
		

Crossrefs

Cf. A019683.

Programs

  • Maple
    evalf(sqrt(Pi)/4,120); # Muniru A Asiru, Sep 22 2018
  • Mathematica
    First[RealDigits[Sqrt[Pi]/4, 10, 100]] (* Paolo Xausa, May 02 2024 *)
  • PARI
    sqrt(Pi)/4 \\ Altug Alkan, Sep 22 2018
    
  • PARI
    intnum(x=0, [oo, -8*I], sin(8*x)/sqrt(x)) \\ Gheorghe Coserea, Sep 23 2018
    
  • PARI
    intnum(x=[0, -1/2], [oo, 8*I], cos(8*x)/sqrt(x)) \\ Gheorghe Coserea, Sep 23 2018

Formula

Equals sqrt(A019683). - Michel Marcus, Aug 31 2014
From A.H.M. Smeets, Sep 22 2018: (Start)
Equals Integral_{x >= 0} sin(8x)/sqrt(x) dx [Gradshteyn and Ryzhik].
Equals Integral_{x >= 0} cos(8x)/sqrt(x) dx [Gradshteyn and Ryzhik]. (End)
From Amiram Eldar, Aug 13 2020: (Start)
Equals Integral_{x=0..oo} x * exp(-x^4) dx.
Equals Integral_{x=0..oo} x^2 * exp(-x^2) dx. (End)