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 1-3 of 3 results.

A073824 Decimal expansion of number with continued fraction expansion 0, 1, 4, 9, ... (the squares).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Aug 12 2002

Keywords

Examples

			0.80431856111715795076768044139...
		

Crossrefs

Cf. A000290 (squares), A052119, A309930, A214070.
The numerators and denominators of convergents to this constant are given by A036245 and A036246 respectively.

Programs

  • Mathematica
    RealDigits[FromContinuedFraction[Range[0,100]^2],10,120][[1]] (* Harvey P. Dale, May 07 2018 *)
  • PARI
    dec_exp(v)= w=contfracpnqn(v); w[1,1]/w[2,1]+0.
    dec_exp(vector(2000,i,(i-1)^2))

A096641 Decimal expansion of number with continued fraction expansion 0, 2, 4, 8, 16, ... (0 and positive powers of 2).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Jun 30 2004

Keywords

Comments

According to the Mc Laughlin-Wyshinski paper, Tasoev proposed continued fractions of the form [a0;a,...,a,a^2,...,a^2,a^3,...,a^3,...], where a0 >= 0, a >= 2 and m >= 1 are integers and each power of a occurs m times. This sequence is for the minimal values a0 = 0, a = 2 and m = 1. Komatsu "derived a closed form for the general case (m >= 1, arbitrary)" and the expression given in (1.2) (where a0=0 and m=1) of the linked paper and which is used in the second PARI/GP program below.

Examples

			0.445934640512202668119554340682617684270408845203438507903263560500661900...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[FromContinuedFraction[{0, 2^Range@ 19}], 10, 111][[1]] (* Robert G. Wilson v, Jan 04 2013 *)
  • PARI
    \p 400
    dec_exp(v)= w=contfracpnqn(v); w[1,1]/w[2,1]+0.
    dec_exp(vector(400,i,if(i==1,0,2^(i-1))))
    /* The following uses Komatsu's expression for given a; a0=0, m=1 */
    {Komatsu(a)=suminf(s=0,a^(-(s+1)^2)*prod(i=1,s,(a^(2*i)-1)^(-1))) /suminf(s=0,a^(-s^2)*prod(i=1,s,(a^(2*i)-1)^(-1)))}
    Komatsu(2) /* generates this sequence's constant */

Formula

From Amiram Eldar, Feb 08 2022: (Start)
Equals A214070 - 1.
Equals 1/A275614 - 1. (End)

A275614 Decimal expansion of number with continued fraction expansion 0, 1, 2, 4, 8, 16, 32, ... (powers of 2).

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			0.69159419242197808428289286692643...
		

Crossrefs

Programs

  • PARI
    terms=sqrtint(bitprecision(1.))+2; \\ terms needed at current precision
    t=contfracpnqn(vector(terms,i,.5<Charles R Greathouse IV, Aug 04 2016

Formula

From Amiram Eldar, Feb 08 2022: (Start)
Equals 1/A214070.
Equals 1/(1 + A096641). (End)

Extensions

Definition corrected by Jianing Song, Mar 29 2025
Showing 1-3 of 3 results.