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.

A248311 Egyptian fraction representation of sqrt(88) (A010539) using a greedy function.

Original entry on oeis.org

9, 3, 22, 490, 354041, 1208217960776, 4186940633541789679127193, 76474669481022771277404940186836961906372402204599, 7594258642248803079765161740266796480079825999844206739159205729216343587849398469094469783005401105
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[ 88]]

A378206 Decimal expansion of the inradius of a triakis tetrahedron with unit shorter edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Nov 21 2024

Keywords

Comments

The triakis tetrahedron is the dual polyhedron of the truncated tetrahedron.

Examples

			0.53300179088902608574609433108459844097593504016042...
		

Crossrefs

Cf. A378204 (surface area), A378205 (volume), A378207 (midradius), A378208 (dihedral angle).
Cf. A010539.

Programs

  • Mathematica
    First[RealDigits[5/Sqrt[88], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["TriakisTetrahedron", "Inradius"], 10, 100]]

Formula

Equals 5/(2*sqrt(22)) = 5/A010539.

A010160 Continued fraction for sqrt(88).

Original entry on oeis.org

9, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1, 1, 1, 2, 18, 2, 1
Offset: 0

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Author

Keywords

Examples

			9.380831519646859109131260227... = 9 + 1/(2 + 1/(1 + 1/(1 + 1/(1 + ...)))). - _Harry J. Smith_, Jun 10 2009
		

Crossrefs

Cf. A010539 Decimal expansion. - Harry J. Smith, Jun 10 2009

Programs

  • Mathematica
    ContinuedFraction[Sqrt[88],300] (* Vladimir Joseph Stephan Orlovsky, Mar 10 2011 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 18000); x=contfrac(sqrt(88)); for (n=0, 20000, write("b010160.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 10 2009

A041156 Numerators of continued fraction convergents to sqrt(88).

Original entry on oeis.org

9, 19, 28, 47, 75, 197, 3621, 7439, 11060, 18499, 29559, 77617, 1426665, 2930947, 4357612, 7288559, 11646171, 30580901, 562102389, 1154785679, 1716888068, 2871673747, 4588561815, 12048797377, 221466914601
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[88], 30]] (* Vincenzo Librandi, Oct 26 2013 *)

Formula

a(n) = 394*a(n-6)-a(n-12). G.f.: -(x^11-9*x^10+19*x^9-28*x^8+47*x^7-75*x^6-197*x^5-75*x^4-47*x^3-28*x^2-19*x-9)/(x^12-394*x^6+1). [Colin Barker, Jul 18 2012]

A041157 Denominators of continued fraction convergents to sqrt(88).

Original entry on oeis.org

1, 2, 3, 5, 8, 21, 386, 793, 1179, 1972, 3151, 8274, 152083, 312440, 464523, 776963, 1241486, 3259935, 59920316, 123100567, 183020883, 306121450, 489142333, 1284406116, 23608452421, 48501310958, 72109763379, 120611074337, 192720837716, 506052749769
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Denominator/@Convergents[Sqrt[88], 50] (* Vladimir Joseph Stephan Orlovsky, Jul 05 2011 *)
    CoefficientList[Series[- (x^10 - 2 x^9 + 3 x^8 - 5 x^7 + 8 x^6 - 21 x^5 - 8 x^4 - 5 x^3 - 3 x^2 - 2 x - 1)/(x^12 - 394 x^6 + 1), {x, 0, 30}], x]  (* Vincenzo Librandi, Oct 24 2013 *)
    LinearRecurrence[{0,0,0,0,0,394,0,0,0,0,0,-1},{1,2,3,5,8,21,386,793,1179,1972,3151,8274},30] (* Harvey P. Dale, Jul 28 2017 *)

Formula

a(n) = 394*a(n-6)-a(n-12). G.f.: -(x^10-2*x^9+3*x^8-5*x^7+8*x^6 -21*x^5 -8*x^4 -5*x^3-3*x^2-2*x-1) / (x^12-394*x^6+1). - Colin Barker, Jul 18 2012
Showing 1-5 of 5 results.