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.

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A040210 Continued fraction for sqrt(226).

Original entry on oeis.org

15, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30
Offset: 0

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Keywords

Examples

			15 + 1/(30 + 1/(30 + 1/(30 + 1/(30 + ...)))) = sqrt(226).
		

Crossrefs

Cf. A041420/A041421 (convergents).

Programs

  • Maple
    with(numtheory): Digits := 300: convert(evalf(sqrt(226)),confrac);

Formula

From Elmo R. Oliveira, Feb 13 2024: (Start)
a(n) = 30 for n >= 1.
G.f.: 15*(1+x)/(1-x).
E.g.f.: 30*exp(x) - 15.
a(n) = 15*A040000(n) = 5*A040006(n) = 3*A040020(n). (End)

A041420 Numerators of continued fraction convergents to sqrt(226).

Original entry on oeis.org

15, 451, 13545, 406801, 12217575, 366934051, 11020239105, 330974107201, 9940243455135, 298538277761251, 8966088576292665, 269281195566541201, 8087401955572528695, 242891339862742402051, 7294827597837844590225, 219087719274998080108801
Offset: 0

Views

Author

Keywords

Crossrefs

Cf. A041421.

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[226], 20]] (* Harvey P. Dale, Feb 02 2012 *)

Formula

a(n) = 30*a(n-1)+a(n-2), n>1 ; a(0)=15, a(1)=451 . G.f.: (15+x)/(1-30*x-x^2). - Philippe Deléham, Nov 22 2008

Extensions

Additional term from Colin Barker, Nov 07 2013
Showing 1-2 of 2 results.