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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A041550 Numerators of continued fraction convergents to sqrt(293).

Original entry on oeis.org

17, 137, 154, 291, 2482, 84679, 679914, 764593, 1444507, 12320649, 420346573, 3375093233, 3795439806, 7170533039, 61159704118, 2086600473051, 16753963488526, 18840563961577, 35594527450103, 303596783562401, 10357885168571737, 83166678132136297
Offset: 0

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Comments

From Johannes W. Meijer, Jun 12 2010: (Start)
The a(n) terms of this sequence can be constructed with the terms of sequence A090306.
For the terms of the periodical sequence of the continued fraction for sqrt(293) see A040275. We observe that its period is five. (End)

Crossrefs

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[293], 30]] (* Vincenzo Librandi, Nov 04 2013 *)

Formula

From Johannes W. Meijer, Jun 12 2010: (Start)
a(5n) = A090306(3n+1), a(5n+1) = (A090306(3n+2) - A090306(3n+1))/2, a(5n+2) = (A090306(3n+2) + A090306(3n+1))/2, a(5n+3) = A090306(3n+2) and a(5n+4) = A090306(3n+3)/2. (End)
G.f.: -(x^9-17*x^8+137*x^7-154*x^6+291*x^5+2482*x^4+291*x^3+154*x^2+137*x+17) / (x^10+4964*x^5-1). - Colin Barker, Nov 08 2013

Extensions

More terms from Colin Barker, Nov 08 2013

A041551 Denominators of continued fraction convergents to sqrt(293).

Original entry on oeis.org

1, 8, 9, 17, 145, 4947, 39721, 44668, 84389, 719780, 24556909, 197175052, 221731961, 418907013, 3572988065, 121900501223, 978776997849, 1100677499072, 2079454496921, 17736313474440, 605114112627881, 4858649214497488, 5463763327125369, 10322412541622857
Offset: 0

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Author

Keywords

Comments

The a(n) terms of this sequence can be constructed with the terms of sequence A178765. For the terms of the periodical sequence of the continued fraction for sqrt(293) see A040275. We observe that its period is five. - Johannes W. Meijer, Jun 12 2010

Crossrefs

Programs

  • Magma
    I:=[1,8,9,17,145,4947,39721,44668,84389,719780]; [n le 10 select I[n] else 4964*Self(n-5)+Self(n-10): n in [1..40]]; // Vincenzo Librandi, Dec 20 2013
  • Mathematica
    Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[293], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Jun 23 2011 *)
    Denominator[Convergents[Sqrt[293 ], 30]] (* Vincenzo Librandi, Dec 20 2013 *)

Formula

a(5n) = A178765(3n), a(5n+1) = (A178765(3n+1) - A178765(3n))/2, a(5n+2) = (A178765(3n+1) + A178765(3n))/2, a(5n+3) = A178765(3n+1) and a(5n+4) = A178765(3n+2)/2. - Johannes W. Meijer, Jun 12 2010
G.f.: -(x^8-8*x^7+9*x^6-17*x^5+145*x^4+17*x^3+9*x^2+8*x+1) / (x^10+4964*x^5-1). - Colin Barker, Nov 12 2013
a(n) = 4964*a(n-5) + a(n-10) for n>9. - Vincenzo Librandi, Dec 20 2013
Showing 1-2 of 2 results.