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 1-4 of 4 results.

A248293 Egyptian fraction representation of sqrt(69) (A010521) using a greedy function.

Original entry on oeis.org

8, 4, 18, 937, 933269, 1035335826584, 1922586201513701668252744, 28276178347455966021225105018046994195665521584589, 833556138210674401337075496134582593689166273775276908669899884379507156146934822563063380503158977
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[ 69]]

A010148 Continued fraction for sqrt(69).

Original entry on oeis.org

8, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1, 3, 3, 16, 3, 3, 1, 4, 1
Offset: 0

Views

Author

Keywords

Examples

			8.306623862918074852584262744... = 8 + 1/(3 + 1/(3 + 1/(1 + 1/(4 + ...)))). - _Harry J. Smith_, Jun 08 2009
		

Crossrefs

Cf. A010521 Decimal expansion. - Harry J. Smith, Jun 08 2009

Programs

  • Mathematica
    ContinuedFraction[Sqrt[69],300] (* Vladimir Joseph Stephan Orlovsky, Mar 08 2011 *)
    PadRight[{8},120,{16,3,3,1,4,1,3,3}] (* Harvey P. Dale, Jan 25 2024 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 22000); x=contfrac(sqrt(69)); for (n=0, 20000, write("b010148.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 08 2009

A041120 Numerators of continued fraction convergents to sqrt(69).

Original entry on oeis.org

8, 25, 83, 108, 515, 623, 2384, 7775, 126784, 388127, 1291165, 1679292, 8008333, 9687625, 37071208, 120901249, 1971491192, 6035374825, 20077615667, 26112990492, 124529577635, 150642568127, 576457282016, 1880014414175, 30656687908816, 93850078140623
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[69], 30]] (* Vincenzo Librandi, Oct 29 2013 *)

Formula

G.f.: -(x^15 -8*x^14 +25*x^13 -83*x^12 +108*x^11 -515*x^10 +623*x^9 -2384*x^8 -7775*x^7 -2384*x^6 -623*x^5 -515*x^4 -108*x^3 -83*x^2 -25*x -8) / (x^16 -15550*x^8 +1). - Colin Barker, Nov 10 2013

Extensions

More terms from Colin Barker, Nov 10 2013

A041121 Denominators of continued fraction convergents to sqrt(69).

Original entry on oeis.org

1, 3, 10, 13, 62, 75, 287, 936, 15263, 46725, 155438, 202163, 964090, 1166253, 4462849, 14554800, 237339649, 726573747, 2417060890, 3143634637, 14991599438, 18135234075, 69397301663, 226327139064, 3690631526687, 11298221719125, 37585296684062, 48883518403187
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Magma
    I:=[1, 3, 10, 13, 62, 75, 287, 936, 15263, 46725, 155438, 202163, 964090, 1166253, 4462849, 14554800]; [n le 16 select I[n] else 15550*Self(n-8)-Self(n-16): n in [1..40]]; // Vincenzo Librandi, Dec 11 2013
  • Mathematica
    Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[69],n]]],{n,1,50}] (* Vladimir Joseph Stephan Orlovsky, Jun 26 2011 *)
    Denominator[Convergents[Sqrt[69], 30]] (* Vincenzo Librandi, Dec 11 2013 *)
    LinearRecurrence[{0,0,0,0,0,0,0,15550,0,0,0,0,0,0,0,-1},{1,3,10,13,62,75,287,936,15263,46725,155438,202163,964090,1166253,4462849,14554800},30] (* Harvey P. Dale, Oct 18 2015 *)

Formula

G.f.: -(x^14 -3*x^13 +10*x^12 -13*x^11 +62*x^10 -75*x^9 +287*x^8 -936*x^7 -287*x^6 -75*x^5 -62*x^4 -13*x^3 -10*x^2 -3*x -1) / (x^16 -15550*x^8 +1). - Colin Barker, Nov 13 2013
a(n) = 15550*a(n-8) - a(n-16). - Vincenzo Librandi, Dec 11 2013

Extensions

More terms from Colin Barker, Nov 13 2013
Showing 1-4 of 4 results.