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 1-5 of 5 results.

A248306 Egyptian fraction representation of sqrt(83) (A010534) using a greedy function.

Original entry on oeis.org

9, 10, 96, 59128, 60492862652, 4028155696720429656035, 17013291528585219660340839803942618904707681, 456446101271720201686717630050003610800823977708023229701905011777418617118028569791687
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[ 83]]

A040073 Continued fraction for sqrt(83).

Original entry on oeis.org

9, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9, 18, 9
Offset: 0

Views

Author

Keywords

Examples

			9.1104335791442988819456261... = 9 + 1/(9 + 1/(18 + 1/(9 + 1/(18 + ...)))). - _Harry J. Smith_, Jun 10 2009
		

Crossrefs

Cf. A010534 Decimal expansion. - Harry J. Smith, Jun 10 2009

Programs

  • Maple
    Digits := 100: convert(evalf(sqrt(N)),confrac,90,'cvgts'):
  • Mathematica
    ContinuedFraction[Sqrt[83],300] (* Vladimir Joseph Stephan Orlovsky, Mar 09 2011 *)
    LinearRecurrence[{0,1},{9,9,18},70] (* or *) PadRight[{9},70,{18,9}] (* Harvey P. Dale, Jan 25 2018 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 45000); x=contfrac(sqrt(83)); for (n=0, 20000, write("b040073.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 10 2009

A041146 Numerators of continued fraction convergents to sqrt(83).

Original entry on oeis.org

9, 82, 1485, 13447, 243531, 2205226, 39937599, 361643617, 6549522705, 59307347962, 1074081786021, 9726043422151, 176142863384739, 1595011813884802, 28886355513311175, 261572211433685377, 4737186161319647961, 42896247663310517026, 776869644100908954429
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[83], 30]] (* Vincenzo Librandi, Oct 29 2013 *)
    LinearRecurrence[{0,164,0,-1},{9,82,1485,13447},20] (* Harvey P. Dale, Apr 12 2022 *)

Formula

G.f.: -(x^3-9*x^2-82*x-9) / (x^4-164*x^2+1). - Colin Barker, Nov 05 2013

Extensions

More terms from Colin Barker, Nov 05 2013

A041147 Denominators of continued fraction convergents to sqrt(83).

Original entry on oeis.org

1, 9, 163, 1476, 26731, 242055, 4383721, 39695544, 718903513, 6509827161, 117895792411, 1067571958860, 19334191051891, 175075291425879, 3170689436717713, 28711280221885296, 519973733430653041, 4708474881097762665, 85272521593190381011, 772161169219811191764
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Magma
    I:=[1, 9, 163, 1476]; [n le 4 select I[n] else 164*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 11 2013
  • Mathematica
    Denominator/@Convergents[Sqrt[83], 50] (* Vladimir Joseph Stephan Orlovsky, Jul 05 2011 *)
    CoefficientList[Series[(1 + 9 x - x^2)/(x^4 - 164 x^2 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 11 2013 *)
    LinearRecurrence[{0,164,0,-1},{1,9,163,1476},30] (* Harvey P. Dale, Nov 09 2017 *)

Formula

G.f.: -(x^2-9*x-1) / (x^4-164*x^2+1). - Colin Barker, Nov 13 2013
a(n) = 164*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 11 2013

A379556 Decimal expansion of the square root of 5312.

Original entry on oeis.org

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

Views

Author

Alonso del Arte, Dec 25 2024

Keywords

Comments

Continued fraction begins 72 then 1, 7, 1, 1, 2, 1, 1, 2, 1, 35, 1, 2, 1, 1, 2, 1, 1, 7, 1, 144, repeated.
The number sqrt(5312) is an algebraic integer in Z[sqrt(83)] as sqrt(5312) = 8 sqrt(83). Z[sqrt(83)] is a unique factorization domain, and 5312 factorizes as (9 - sqrt(83))^6 (9 + sqrt(83))^6 sqrt(83)^2.

Examples

			72.883468633154391...
		

Crossrefs

Cf. A010534, the square root of 83.

Programs

  • Magma
    SetDefaultRealField(RealField(100)); Sqrt(5312); // Vincenzo Librandi, Jan 02 2025
  • Mathematica
    RealDigits[Sqrt[5312], 10, 100][[1]]
  • Scala
    import java.math.{BigDecimal, MathContext, RoundingMode}
    val num = BigDecimal.valueOf(5312)
    val mc = new MathContext(128, RoundingMode.HALF_EVEN)
    val root = num.sqrt(mc)
    root.toString.replace(".", "").toCharArray.toList
    
Showing 1-5 of 5 results.