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.

A375820 Decimal expansion of 333/106.

Original entry on oeis.org

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

Views

Author

Stefano Spezia, Aug 30 2024

Keywords

Comments

Approximation of Pi accurate up to five digits.
Periodic of period [4, 1, 5, 0, 9, 4, 3, 3, 9, 6, 2, 2, 6] of length 13.

Examples

			3.1415094339622641509433962264150943396226415...
		

References

  • Alfred S. Posamentier, Math Charmers, Tantalizing Tidbits for the Mind, Prometheus Books, NY, 2003, page 154-155.
  • David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987. See p. 49.

Crossrefs

Programs

  • Mathematica
    RealDigits[333/106,10,100][[1]]
  • Python
    def A375820(n): return (2, 2 ,6, 4, 1, 5, 0, 9, 4, 3, 3, 9, 6)[n%13] if n>2 else 5-(n<<1) # Chai Wah Wu, Aug 30 2024

Formula

Equals (2*355 - 377)/(2*113 - 120), where A068079 = 355/113 and A210622 = 377/120 [Adriaen Metius]. See Wells.