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.

A040042 Continued fraction for sqrt(50) = 5*sqrt(2).

Original entry on oeis.org

7, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14
Offset: 0

Views

Author

Keywords

Examples

			7.07106781186547524400844... = 7 + 1/(14 + 1/(14 + 1/(14 + 1/(14 + ...)))). - _Harry J. Smith_, Jun 01 2009
		

References

  • James J. Tattersall, Elementary Number Theory in Nine Chapters, Cambridge University Press, 1999, page 276.

Crossrefs

Cf. A010503 (decimal expansion), A041084/A041085 (convergents), A248275 (Egyptian fraction).
Cf. A040000.

Programs

  • Maple
    Digits := 100: convert(evalf(sqrt(N)),confrac,90,'cvgts'):
  • Mathematica
    ContinuedFraction[Sqrt[50],300] (* Vladimir Joseph Stephan Orlovsky, Mar 07 2011 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 47000); x=contfrac(sqrt(50)); for (n=0, 20000, write("b040042.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 01 2009

Formula

From Elmo R. Oliveira, Feb 07 2024: (Start)
a(n) = 14 = A010853(n) for n >= 1.
G.f.: 7*(1+x)/(1-x).
E.g.f.: 14*exp(x) - 7.
a(n) = 7*A040000(n). (End)