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 1-2 of 2 results.

A010525 Decimal expansion of square root of 73.

Original entry on oeis.org

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

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Comments

Continued fraction expansion is 8 followed by {1, 1, 5, 5, 1, 1, 16} repeated. - Harry J. Smith, Jun 08 2009

Examples

			8.544003745317531167871648326239706434594455329533282241908651253771648....
		

Crossrefs

Cf. A010151 (continued fraction).

Programs

  • Mathematica
    RealDigits[N[73^(1/2),200]][[1]] (* Vladimir Joseph Stephan Orlovsky, Jan 23 2012 *)
  • PARI
    default(realprecision, 20080); x=sqrt(73); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b010525.txt", n, " ", d));  \\ Harry J. Smith, Jun 08 2009

Extensions

Final digits of sequence corrected using the b-file. - N. J. A. Sloane, Aug 30 2009

A041129 Denominators of continued fraction convergents to sqrt(73).

Original entry on oeis.org

1, 1, 2, 11, 57, 68, 125, 2068, 2193, 4261, 23498, 121751, 145249, 267000, 4417249, 4684249, 9101498, 50191739, 260060193, 310251932, 570312125, 9435245932, 10005558057, 19440803989, 107209578002, 555488693999, 662698272001, 1218186966000, 20153689728001
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Magma
    I:=[1,1,2,11,57,68,125,2068,2193,4261,23498,121751,145249, 267000]; [n le 14 select I[n] else 2136*Self(n-7)+Self(n-14): n in [1..40]]; // Vincenzo Librandi, Dec 11 2013
  • Mathematica
    Denominator/@Convergents[Sqrt[73], 50] (* Vladimir Joseph Stephan Orlovsky, Jul 05 2011 *)
    CoefficientList[Series[-(x^12 - x^11 + 2 x^10 - 11 x^9 + 57 x^8 - 68 x^7 + 125 x^6 + 68 x^5 + 57 x^4 + 11 x^3 + 2 x^2 + x + 1)/(x^14 + 2136 x^7 - 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 11 2013 *)

Formula

G.f.: -(x^12 -x^11 +2*x^10 -11*x^9 +57*x^8 -68*x^7 +125*x^6 +68*x^5 +57*x^4 +11*x^3 +2*x^2 +x +1) / (x^14 +2136*x^7 -1). - Colin Barker, Nov 13 2013
a(n) = 2136*a(n-7) + a(n-14). - Vincenzo Librandi, Dec 11 2013
Showing 1-2 of 2 results.