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.

Showing 1-2 of 2 results.

A010478 Decimal expansion of square root of 22.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

Continued fraction expansion is 4 followed by {1, 2, 4, 2, 1, 8} repeated (A010126). - Harry J. Smith, Jun 03 2009

Examples

			4.690415759823429554565630113544466280588228353411737153605701891017024....
		

Crossrefs

Cf. A010126 (continued fraction), A248250 (Egyptian fraction), A020779 (reciprocal).

Programs

  • Mathematica
    RealDigits[N[Sqrt[22],200]][[1]] (* Vladimir Joseph Stephan Orlovsky, Feb 22 2011 *)
  • PARI
    default(realprecision, 20080); x=sqrt(22); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b010478.txt", n, " ", d));  \\ Harry J. Smith, Jun 03 2009

A010126 Continued fraction for sqrt(22).

Original entry on oeis.org

4, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2, 4, 2, 1, 8, 1, 2
Offset: 0

Views

Author

Keywords

Examples

			4.690415759823429554565630113... = 4 + 1/(1 + 1/(2 + 1/(4 + 1/(2 + ...)))). - _Harry J. Smith_, Jun 03 2009
		

References

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

Crossrefs

Cf. A041034/A041035 (convergents), A248250 (Egyptian fraction), A010478 (decimal expansion).

Programs

  • Mathematica
    ContinuedFraction[Sqrt[22],300] (* Vladimir Joseph Stephan Orlovsky, Mar 05 2011 *)
    PadRight[{4},120,{8,1,2,4,2,1}] (* Harvey P. Dale, Jul 02 2019 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 18000); x=contfrac(sqrt(22)); for (n=0, 20000, write("b010126.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 03 2009

Formula

From Amiram Eldar, Nov 12 2023: (Start)
Multiplicative with a(2^e) = 2, a(3^e) = 4, and a(p^e) = 1 for p >= 5.
Dirichlet g.f.: zeta(s) * (1 + 1/2^s) * (1 + 1/3^(s-1)). (End)
G.f.: (4 + x + 2*x^2 + 4*x^3 + 2*x^4 + x^5 + 4*x^6)/(1 - x^6). - Stefano Spezia, Jul 26 2025
Showing 1-2 of 2 results.