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.

A333202 Decimal expansion of arclength from (0,0) to (1,1) on y = x^2.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, May 13 2020

Keywords

Examples

			Equals 1.478942857544597433827906...
		

Crossrefs

Programs

  • Mathematica
    s = Integrate[Sqrt[1 + 4 x^2], {x, 0, 1}]
    r = N[s, 200]
    RealDigits[r][[1]]
  • PARI
    sqrt(5)/2 + asinh(2)/4 \\ Charles R Greathouse IV, Sep 02 2024

Formula

arclength = (2 sqrt(5) + arcsinh(2))/4.
arclength = (2 sqrt(5) + log(2 + sqrt(5)))/4.