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 1-7 of 7 results.

A248260 Egyptian fraction representation of sqrt(33) (A010488) using a greedy function.

Original entry on oeis.org

5, 2, 5, 23, 923, 1039448, 1349594009502, 1841990944227649463764190, 5531888379621714420992617902281239594988386275117, 172423874327527416450254906621893256497583527925050132860644029730203113536215473159687066655835408
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[ 33]]

A235162 Decimal expansion of (sqrt(33) + 1) / 2.

Original entry on oeis.org

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

Views

Author

Jaroslav Krizek, Feb 06 2014

Keywords

Comments

Solution of y^2 - y - 8 = 0.
Decimal expansion of sqrt(8 + sqrt(8 + sqrt(8 + sqrt(8 + ... )))).
The sequence with a(1) = 2 is decimal expansion of sqrt(8 - sqrt(8 - sqrt(8 - sqrt(8 - ... )))).
A basis for the integers of the real quadratic number field K(sqrt(33)) is
<1, omega(33)>, where omega(33) = (1 + sqrt(33))/2. - Wolfdieter Lang, Feb 11 2020

Examples

			3.37228132326901432992530573410946465911013222899139618384993873528...
		

Crossrefs

Programs

  • MATLAB
    val = vpa((sqrt(sym(33))+1)/2,10001); list = char(val)-'0'; list = list([1,3:end-1]); % Christopher M. Conrey, Jan 26 2022
  • Mathematica
    RealDigits[(1 + Sqrt[33])/2, 10, 130]

A010131 Continued fraction for sqrt(33).

Original entry on oeis.org

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

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Author

Keywords

Examples

			5.74456264653802865985061146... = 5 + 1/(1 + 1/(2 + 1/(1 + 1/(10 + ...)))). - _Harry J. Smith_, Jun 04 2009
		

References

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

Crossrefs

Cf. A010488 (decimal expansion).

Programs

  • Mathematica
    ContinuedFraction[Sqrt[33],300] (* Vladimir Joseph Stephan Orlovsky, Mar 06 2011 *)
    LinearRecurrence[{0,0,0,1},{5,1,2,1,10},100] (* or *) PadRight[{5},100,{10,1,2,1}] (* Harvey P. Dale, Dec 31 2017 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 17000); x=contfrac(sqrt(33)); for (n=0, 20000, write("b010131.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 04 2009

Formula

From Amiram Eldar, Nov 12 2023: (Start)
Multiplicative with a(2) = 2, a(2^e) = 10 for e >= 2, and a(p^e) = 1 for an odd prime p.
Dirichlet g.f.: zeta(s) * (1 + 1/2^(2*s-3) + 1/2^s). (End)
G.f.: (5 + x + 2*x^2 + x^3 + 5*x^4)/(1 - x^4). - Stefano Spezia, Jul 26 2025

A041054 Numerators of continued fraction convergents to sqrt(33).

Original entry on oeis.org

5, 6, 17, 23, 247, 270, 787, 1057, 11357, 12414, 36185, 48599, 522175, 570774, 1663723, 2234497, 24008693, 26243190, 76495073, 102738263, 1103877703, 1206615966, 3517109635, 4723725601, 50754365645
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Numerator[FromContinuedFraction[ContinuedFraction[Sqrt[33], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Mar 18 2011 *)
    Numerator[Convergents[Sqrt[33],30]] (* Harvey P. Dale, Oct 25 2011 *)
    CoefficientList[Series[- (x^7 - 5 x^6 + 6 x^5 - 17 x^4 - 23 x^3 - 17 x^2 - 6 x - 5)/(x^8 - 46 x^4 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 23 2013 *)

Formula

a(n) = 46*a(n-4)-a(n-8). G.f.: -(x^7-5*x^6+6*x^5-17*x^4-23*x^3-17*x^2-6*x-5)/(x^8-46*x^4+1). [Colin Barker, Jul 16 2012]

A041055 Denominators of continued fraction convergents to sqrt(33).

Original entry on oeis.org

1, 1, 3, 4, 43, 47, 137, 184, 1977, 2161, 6299, 8460, 90899, 99359, 289617, 388976, 4179377, 4568353, 13316083, 17884436, 192160443, 210044879, 612250201, 822295080, 8835201001, 9657496081, 28150193163
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[33], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Mar 18 2011 *)
    Denominator[Convergents[Sqrt[33], 30]] (* Vincenzo Librandi, Oct 23 2013 *)
    LinearRecurrence[{0,0,0,46,0,0,0,-1},{1,1,3,4,43,47,137,184},30] (* Harvey P. Dale, Apr 24 2022 *)

Formula

a(n) = 46*a(n-4)-a(n-8). G.f.: -(x^2-x-1)*(x^4+4*x^2+1)/(x^8-46*x^4+1). [Colin Barker, Jul 16 2012]

A236290 Decimal expansion of (sqrt(33) - 1) / 2.

Original entry on oeis.org

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

Views

Author

Jaroslav Krizek, Feb 07 2014

Keywords

Comments

Decimal expansion of sqrt(8 - sqrt(8 - sqrt(8 - sqrt(8 - ... )))).
The sequence with a(1) = 3 is decimal expansion of sqrt(8 + sqrt(8 + sqrt(8 + sqrt(8 + ... )))).
A quadratic integer with minimal polynomial x^2 + x - 8. - Charles R Greathouse IV, Apr 21 2016
Triangular root of 4. - Stefano Spezia, Sep 05 2025

Examples

			2.37228132326901432992530573410946465911013222899139618384993873528...
		

Crossrefs

Programs

Formula

Equals A235162 - 1.

A357418 Decimal expansion of (207 - 33*sqrt(33))/32.

Original entry on oeis.org

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

Views

Author

Stefano Spezia, Sep 27 2022

Keywords

Comments

This constant expresses the Turán density of the extension of the 4-graph formed by 3 disjoint edges. For the details about the construction of the extension, see Wu's article.

Examples

			0.54466977075765794452905692339922914058535...
		

Crossrefs

Cf. A010488.

Programs

  • Mathematica
    First[RealDigits[N[(207 - 33 Sqrt[33])/32, 95]]]

Formula

Minimal polynomial: 16*x^2 - 207*x + 108. - Stefano Spezia, Aug 03 2025
Showing 1-7 of 7 results.