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 1-10 of 12 results. Next

A248256 Egyptian fraction representation of sqrt(29) (A010484) using a greedy function.

Original entry on oeis.org

5, 3, 20, 547, 301184, 147558270953, 86497522148984105061516, 8551929116782420428265616715584087619312418621, 99749931990938468116836650873165146389082138700427586581720209715910550531363814159816345424
Offset: 0

Views

Author

Robert G. Wilson v, Oct 04 2014

Keywords

Crossrefs

Egyptian fraction representations of the square roots: A006487, A224231, A248235-A248322.
Egyptian fraction representations of the cube roots: A129702, A132480-A132574.

Programs

  • Mathematica
    Egyptian[nbr_] := Block[{lst = {IntegerPart[nbr]}, cons = N[ FractionalPart[ nbr], 2^20], denom, iter = 8}, While[ iter > 0, denom = Ceiling[ 1/cons]; AppendTo[ lst, denom]; cons -= 1/denom; iter--]; lst]; Egyptian[ Sqrt[ 29]]

A041046 Numerators of continued fraction convergents to sqrt(29).

Original entry on oeis.org

5, 11, 16, 27, 70, 727, 1524, 2251, 3775, 9801, 101785, 213371, 315156, 528527, 1372210, 14250627, 29873464, 44124091, 73997555, 192119201, 1995189565, 4182498331, 6177687896, 10360186227, 26898060350
Offset: 0

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Author

Keywords

Comments

From Johannes W. Meijer, Jun 12 2010: (Start)
The terms of this sequence can be constructed with the terms of sequence A087130.
For the terms of the periodical sequence of the continued fraction for sqrt(29) see A010128. We observe that its period is five. The decimal expansion of sqrt(29) is A010484. (End)

Crossrefs

Programs

  • Mathematica
    Table[Numerator[FromContinuedFraction[ContinuedFraction[Sqrt[29],n]]],{n,1,50}] (* Vladimir Joseph Stephan Orlovsky, Mar 18 2011 *)
    Numerator[Convergents[Sqrt[29], 30]] (* Vincenzo Librandi, Oct 28 2013 *)
    LinearRecurrence[ {0,0,0,0,140,0,0,0,0,1},{5,11,16,27,70,727,1524,2251,3775,9801},30] (* Harvey P. Dale, Jun 10 2021 *)

Formula

a(5*n) = A087130(3*n+1), a(5*n+1) = (A087130(3*n+2) - A087130(3*n+1))/2, a(5*n+2) = ( A087130(3*n+2) + A087130(3*n+1))/2, a(5*n+3) = A087130(3*n+2) and a(5*n+4) = A087130(3*n+3)/2. - Johannes W. Meijer, Jun 12 2010
G.f.: (5 + 11*x + 16*x^2 + 27*x^3 + 70*x^4 + 27*x^5 - 16*x^6 + 11*x^7 - 5*x^8 + x^9)/(1 - 140*x^5 - x^10) - Peter J. C. Moses, Jul 29 2013

A041047 Denominators of continued fraction convergents to sqrt(29).

Original entry on oeis.org

1, 2, 3, 5, 13, 135, 283, 418, 701, 1820, 18901, 39622, 58523, 98145, 254813, 2646275, 5547363, 8193638, 13741001, 35675640, 370497401, 776670442, 1147167843, 1923838285, 4994844413, 51872282415
Offset: 0

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Author

Keywords

Comments

The terms of this sequence can be constructed with the terms of sequence A052918.
For the terms of the periodical sequence of the continued fraction for sqrt(29) see A010128. We observe that its period is five. The decimal expansion of sqrt(29) is A010484. - Johannes W. Meijer, Jun 12 2010

Crossrefs

Programs

  • Magma
    I:=[1, 2, 3, 5, 13, 135, 283, 418, 701, 1820]; [n le 10 select I[n] else 140*Self(n-5)+Self(n-10): n in [1..50]]; // Vincenzo Librandi, Dec 10 2013
  • Mathematica
    Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[29],n]]],{n,1,50}] (* Vladimir Joseph Stephan Orlovsky, Mar 18 2011 *)
    Denominator[Convergents[Sqrt[29], 30]] (* Vincenzo Librandi, Dec 10 2013 *)

Formula

a(5*n) = A052918(3*n), a(5*n+1) = (A052918(3*n+1) - A052918(3*n))/2, a(5*n+2) = (A052918(3*n+1) + A052918(3*n))/2, a(5*n+3) = A052918(3*n+1) and a(5*n+4) = A052918(3*n+2)/2. - Johannes W. Meijer, Jun 12 2010
G.f.: (1 + 2*x + 3*x^2 + 5*x^3 + 13*x^4 - 5*x^5 + 3*x^6 - 2*x^7 + x^8)/(1 - 140*x^5 - x^10). - Peter J. C. Moses, Jul 29 2013
a(n) = 140*a(n-5) + a(n-10). - Vincenzo Librandi, Dec 10 2013

A010538 Decimal expansion of square root of 87.

Original entry on oeis.org

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

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Author

Keywords

Comments

Continued fraction expansion is 9 followed by {3, 18} repeated. - Harry J. Smith, Jun 10 2009

Examples

			9.3273790530888150455544755423205569832762406...
		

Crossrefs

Cf. A040077 (continued fraction).

Programs

Formula

Equals A002194 * A010484. - R. J. Mathar, Jun 08 2020

A176910 Decimal expansion of sqrt(145).

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, Apr 28 2010

Keywords

Comments

Continued fraction expansion of sqrt(145) is 12 followed by A010863.

Examples

			sqrt(145) = 12.04159457879229548012...
		

Crossrefs

Cf. A002163 (decimal expansion of sqrt(5)), Cf. A010484 (decimal expansion of sqrt(29)), A176907 (decimal expansion of (9+sqrt(145))/16), A176908 (decimal expansion of (7+sqrt(145))/16), A010863 (all 24's sequence).

Programs

  • Mathematica
    RealDigits[Sqrt[145],10,120][[1]] (* Harvey P. Dale, Oct 15 2023 *)

A374359 a(1) = 2, a(n) = 5 for n > 1.

Original entry on oeis.org

2, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
Offset: 1

Views

Author

Stefano Spezia, Jul 06 2024

Keywords

Comments

Decimal expansion of 23/9, which is an approximation of the 5th root of 109 (A374357).
Simple continued fraction expansion of (1 + sqrt(29))/14 = (1 + A010484)/14.

Examples

			2.555555555555555555555555555555555555555...
		

Crossrefs

Cf. A374357 (decimal expansion of the 5th root of 109), A374358 (continued fraction of the 5th root of 109).
Cf. A010484.
Essentially the same as A021022 and A010716.

Programs

  • Mathematica
    LinearRecurrence[{1},{2,5},100]

Formula

G.f.: x*(2 + 3*x)/(1 - x).
a(n) = a(n-1) for n > 2.
E.g.f.: 5*exp(x) - 3*x - 5.

A010128 Continued fraction for sqrt(29).

Original entry on oeis.org

5, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10, 2, 1, 1, 2, 10
Offset: 0

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Author

Keywords

Examples

			5.385164807134504031250710491... = 5 + 1/(2 + 1/(1 + 1/(1 + 1/(2 + ...)))). - _Harry J. Smith_, Jun 04 2009
		

References

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

Crossrefs

Cf. A010484 (Decimal expansion). - Harry J. Smith, Jun 04 2009

Programs

  • Mathematica
    ContinuedFraction[Sqrt[29], 300] (* Vladimir Joseph Stephan Orlovsky, Mar 06 2011 *)
    PadRight[{5},120,{10,2,1,1,2}] (* Harvey P. Dale, Apr 18 2017 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 18000); x=contfrac(sqrt(29)); for (n=0, 20000, write("b010128.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 04 2009

Formula

G.f.: (5 + 2*x + x^2 + x^3 + 2*x^4 + 5*x^5)/(1 - x^5). - Stefano Spezia, Jul 26 2025

A085551 Decimal expansion of (sqrt(29)-5)/2.

Original entry on oeis.org

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

Views

Author

Cino Hilliard, Jul 04 2003

Keywords

Examples

			0.19258240356725201562535524577...
		

Crossrefs

Cf. A010484 (sqrt(29)), A052918.

Programs

Formula

Equals Sum_{n>=1}(-1)^(n-1)/(A052918(n)*A052918(n+1)). - Vladimir Shevelev, Feb 23 2013

A178593 Decimal expansion of (7 + 5*sqrt(29))/26.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, May 31 2010

Keywords

Comments

Continued fraction expansion of (7+5*sqrt(29))/26 is A084101.

Examples

			(7+5*sqrt(29))/26 = 1.30483938598740462139...
		

Crossrefs

Cf. A010484 (decimal expansion of sqrt(29)), A084101 (repeat 1, 3, 3, 1).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); (7+5*Sqrt(29))/26; // G. C. Greubel, Jan 29 2019
    
  • Mathematica
    RealDigits[(7+5*Sqrt[29])/26,10,120][[1]] (* Harvey P. Dale, Apr 09 2015 *)
  • PARI
    default(realprecision, 100); (7+5*sqrt(29))/26 \\ G. C. Greubel, Jan 29 2019
    
  • Sage
    numerical_approx((7+5*sqrt(29))/26, digits=100) # G. C. Greubel, Jan 29 2019

A367454 Decimal expansion of (-1 + sqrt(29))/14 = 1/A223140.

Original entry on oeis.org

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

Views

Author

Wolfdieter Lang, Jan 05 2024

Keywords

Comments

c^n = 7*A(-(n+1)) + A(-n)*phi29, for n >= 0, where phi29 = A223140, and A(-n) = A015442(-n) = sqrt(-7)^(-(n+1))*S(-(n+1), 1/sqrt(-7)) = -(i/sqrt(7))^(n+1)*S(n-1, i/sqrt(7)), with i = sqrt(-1) and the S-Chebyshev polynomials (see A049310), where S(-n, x) = -S(n-2, x), for n >= 1, and S(n, -x) = (-1)^n*S(n, x).

Examples

			c = 0.3132260576524645736607650351100235397353657258317706312628...
		

Crossrefs

Programs

  • Mathematica
    Flatten[First[RealDigits[(-1 + Sqrt[29])/14,10,96]]] (* Stefano Spezia, Jan 05 2024 *)

Formula

c = 1/phi29 = (-1 + phi(29))/7, with phi29 = A223140.
Showing 1-10 of 12 results. Next