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.

A040870 Continued fraction for sqrt(901).

Original entry on oeis.org

30, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60
Offset: 0

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Keywords

Examples

			30 + 1/(60 + 1/(60 + 1/(60 + 1/(60 + ...)))) = sqrt(901).
		

Crossrefs

Cf. A040000, A042740/A042741 (convergents).

Programs

  • Maple
    with(numtheory): Digits := 300: convert(evalf(sqrt(901)),confrac);
  • Mathematica
    Block[{$MaxExtraPrecision=1000},ContinuedFraction[Sqrt[901],100]] (* or *) PadRight[{30},100,60] (* Harvey P. Dale, Sep 01 2014 *)

Formula

a(n) = 30*A040000(n). - Stefano Spezia, May 14 2023
From Elmo R. Oliveira, Feb 16 2024: (Start)
a(n) = 60 for n >= 1.
G.f.: 30*(1+x)/(1-x).
E.g.f.: 60*exp(x) - 30. (End)

A042740 Numerators of continued fraction convergents to sqrt(901).

Original entry on oeis.org

30, 1801, 108090, 6487201, 389340150, 23366896201, 1402403112210, 84167553628801, 5051455620840270, 303171504804045001, 18195341743863540330, 1092023676136616464801, 65539615909940851428390, 3933468978272587702168201, 236073678312265202981520450, 14168354167714184766593395201
Offset: 0

Views

Author

Keywords

Crossrefs

Cf. A042741.

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[901], 30]] (* Vincenzo Librandi, Dec 03 2013 *)

Formula

From Philippe Deléham, Nov 23 2008: (Start)
a(n) = 60*a(n-1)+a(n-2) for n>1, a(0)=30, a(1)=1801.
G.f.: (30+x)/(1-60*x-x^2). (End)
E.g.f.: exp(30*x)*(30*cosh(sqrt(901)*x) + sqrt(901)*sinh(sqrt(901)*x)). - Stefano Spezia, May 14 2023
Showing 1-2 of 2 results.