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.

A010515 Decimal expansion of square root of 62.

Original entry on oeis.org

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

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Comments

Sqrt(62) = 787400 * Sum_{n>=0} (A001790(n)/2^A005187(floor(n/2)) * 10^(-6n-5)) where A001790(n) are numerators in expansion of 1/sqrt(1-x) and the denominators in expansion of 1/sqrt(1-x) are 2^A005187(n). 786400 = 62*12700, see A020819 (expansion of 1/sqrt(62)). - Gerald McGarvey, Jan 01 2005
Continued fraction expansion is 7 followed by {1, 6, 1, 14} repeated. - Harry J. Smith, Jun 07 2009

Examples

			7.874007874011811019685034448812007863681086122020853794598842550313760...
		

Crossrefs

Cf. A010146 Continued fraction.

Programs

  • Mathematica
    RealDigits[N[62^(1/2),200]][[1]] (* Vladimir Joseph Stephan Orlovsky, Jan 22 2012 *)
  • PARI
    { default(realprecision, 20080); x=sqrt(62); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b010515.txt", n, " ", d)); } \\ Harry J. Smith, Jun 07 2009

Extensions

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

A041109 Denominators of continued fraction convergents to sqrt(62).

Original entry on oeis.org

1, 1, 7, 8, 119, 127, 881, 1008, 14993, 16001, 110999, 127000, 1888999, 2015999, 13984993, 16000992, 237998881, 253999873, 1761998119, 2015997992, 29985970007, 32001967999, 221997778001, 253999746000, 3777994222001, 4031993968001, 27969958030007
Offset: 0

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Programs

  • Magma
    I:=[1, 1, 7, 8, 119, 127, 881, 1008]; [n le 8 select I[n] else 126*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 11 2013
  • Mathematica
    Denominator[Convergents[Sqrt[62], 30]] (* Vincenzo Librandi, Dec 11 2013 *)
    LinearRecurrence[{0,0,0,126,0,0,0,-1},{1,1,7,8,119,127,881,1008},30] (* Harvey P. Dale, Oct 26 2016 *)

Formula

G.f.: -(x^2-x-1)*(x^4+8*x^2+1) / (x^8-126*x^4+1). - Colin Barker, Nov 12 2013
a(n) = 126*a(n-4) - a(n-8). - Vincenzo Librandi, Dec 11 2013

Extensions

More terms from Colin Barker, Nov 12 2013
Showing 1-2 of 2 results.