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.

A086773 Decimal expansion of the continued fraction 1/(Pi+1/(Pi+1/(Pi+1/(Pi+...)))).

Original entry on oeis.org

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

Views

Author

Cino Hilliard, Aug 03 2003

Keywords

Comments

Repeat s = s + Pi; s=1/s. The initial value of s is irrelevant.
Solves log(x+Pi) = -log(x). This equation represents the first (by absolute value) self-intersection of the spiral defined by the polar equation r=log(theta), and this constant is the smaller value of theta in the self-intersection. - Jeremy Tan, Sep 03 2016

Examples

			1
------
Pi + 1
     ------
     Pi + 1
          --------
           Pi + ...
		

Crossrefs

Cf. A188722.

Programs

  • Mathematica
    RealDigits[N[(Sqrt[Pi^2 + 4] - Pi)/2, 120]] // First (* Michael De Vlieger, Mar 31 2015 *)
  • PARI
    default(realprecision, 2000); f(n) = s=0; for(x=1,n,s=s+Pi; s=1/s); print(s)

Formula

Equals (sqrt(Pi^2+4)-Pi)/2 = 0.2912995... . - R. J. Mathar, Sep 15 2012