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.

Previous Showing 11-19 of 19 results.

A355512 Sum of numerator and denominator in the convergents of the approximation of log(2)/log(3) by a continued fraction.

Original entry on oeis.org

2, 3, 5, 13, 31, 106, 137, 791, 1719, 40328, 82375, 205078, 287453, 492531, 27376658, 27869189, 138853414, 444429431, 583282845, 1027712276, 15998966985, 17026679261, 169239080334, 355504839929, 1946763279979, 13982847799782, 15929611079761, 29912458879543, 135579446597933
Offset: 1

Views

Author

Hugo Pfoertner, Jul 05 2022

Keywords

Crossrefs

Cf. A355514 for the relation to potential cycle lengths of the 3x+1 problem.

Programs

  • PARI
    a355512(upto) = {my(q=log(2)/log(3), fa=oo); for (denmax=1, upto, my(f=bestappr(q,denmax)); if (fa!=f, print1(numerator(f)+denominator(f),", "); fa=f))};
    \\ needs increased precision for larger terms
    a355512(10^6)
    
  • PARI
    \\ See also A005663 and A005664 for efficient code.

A355513 Sum of numerator and denominator in a rational approximation j/k of q = log(2)/log(3), such that abs(j/k - q) is a new minimum.

Original entry on oeis.org

2, 3, 5, 8, 13, 18, 31, 75, 106, 137, 517, 654, 791, 928, 1719, 21419, 23138, 24857, 26576, 28295, 30014, 31733, 33452, 35171, 36890, 38609, 40328, 82375, 205078, 287453, 492531, 14078321, 14570852, 15063383, 15555914, 16048445, 16540976, 17033507, 17526038, 18018569
Offset: 1

Views

Author

Hugo Pfoertner, Jul 05 2022

Keywords

Crossrefs

Programs

  • PARI
    a355513(upto) = {my(q=log(2)/log(3), dmin=oo);for (m=1, upto, my(n=round(m*q), qq=n/m, d=abs(qq-q)); if(d
    				

A355515 Sum of numerator and denominator in a rational approximation j/k of q = log(2)/log(3), such that j/k - q is a new minimum, i.e., q is approximated from above.

Original entry on oeis.org

2, 5, 18, 31, 137, 928, 1719, 42047, 82375, 287453, 779984, 1272515, 1765046, 2257577, 2750108, 3242639, 3735170, 4227701, 4720232, 5212763, 5705294, 6197825, 6690356, 7182887, 7675418, 8167949, 8660480, 9153011, 9645542, 10138073, 10630604, 11123135, 11615666, 12108197
Offset: 1

Views

Author

Hugo Pfoertner, Jul 05 2022

Keywords

Crossrefs

Programs

  • PARI
    a355515(upto) = {my(q=log(2)/log(3), dmin=oo); for (m=1, upto, my(n=ceil(m*q), qq=n/m, d=qq-q); if (d
    				

A152549 Decimal expansion of log_3(18).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 28 2009, based on a posting by Michael Kleber to the Math Fun Mailing List

Keywords

Comments

Hausdorff dimension of Jeannine Mosely's origami model of Menger's sponge.

Examples

			2.6309297535714574370995271143427608542995856401318804278706...
		

Programs

Formula

Equals 2+A102525. - R. J. Mathar, Oct 02 2023

A102447 Decimal expansion of log_3(20).

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Feb 23 2005

Keywords

Comments

Hausdorff dimension of Menger sponge.

Examples

			2.72683302786084204139609463636416210490710364692981054479420028247...
		

References

  • Manfred Schroeder, Fractals, Chaos, Power Laws, Freeman,1991, p. 179.
  • Ian Stewart, Does God Play Dice?, The New Mathematics of Chaos, 2nd Ed., Blackwell Pub'l., Malden MA, 2002, p. 207.

Crossrefs

Programs

  • Mathematica
    RealDigits[ Log[3, 20], 10, 111][[1]]
  • PARI
    log(20)/log(3) \\ Michel Marcus, Jul 19 2020

A153459 Decimal expansion of log_3 (6).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Comments

Equals the Hausdorff dimension of Pascal's triangle modulo 3 (A083093). In general, the dimension of Pascal's triangle modulo a prime p is log(p*(p+1)/2) / log(p) (see Reiter link, theorem 2 page 117). - Bernard Schott, Dec 01 2022

Examples

			1.6309297535714574370995271143427608542995856401318804278706...
		

Crossrefs

Programs

Formula

Equals A016629 / A002391 = 1 + A102525. - Bernard Schott, Dec 01 2022

A154196 Decimal expansion of log_3 (12).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			2.2618595071429148741990542286855217085991712802637608557413...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Log[3, 12], 10, 120][[1]] (* Vincenzo Librandi, Aug 29 2013 *)

Formula

From Amiram Eldar, May 04 2023: (Start)
Equals 1 + 2 * log_3(2) = 1 + 2 * A102525.
Equasl 1/A153015. (End)

A346640 Decimal expansion of 2 - log_3(2).

Original entry on oeis.org

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

Views

Author

Kevin Ryde, Jul 26 2021

Keywords

Comments

Bedford and McMullen show this is the metric dimension of Hironaka's curve and equivalent carpets (see A346639).

Examples

			1.3690702464285425629004728856572391...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[2 - Log[3, 2], 10, 105][[1]] (* Amiram Eldar, Jul 27 2021 *)
  • PARI
    2 - log(2)/log(3) \\ Michel Marcus, Jul 27 2021

Formula

Equals 2 - A102525.
Equals Sum_{d=1..2} d*log(1+1/d)/log(3). Compare with A213201. - Michel Marcus, Dec 25 2022

A228375 Decimal expansion of log_3(25).

Original entry on oeis.org

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

Views

Author

Vincenzo Librandi, Aug 29 2013

Keywords

Examples

			2.92994704143585433439408081535728079261586473333209937810578078959098...
		

Crossrefs

Cf. decimal expansion of log_3(m): A102525 (m=2), A100831 (m=4), A113209 (m=5), A153459 (m=6), A152565 (m=7), A113210 (m=8), A152566 (m=10), A154175 (m=11), A154196 (m=12), A154217 (m=13), A154463 (m=14), A154542 (m=15), A154751 (m=16), A154848 (m=17), A152549 (m=18), A155003 (m=19), A102447 (m=20), A155541 (m=21), A155694 (m=22), A155808 (m=23), A155922 (m=24), this sequence, A152564 (m=26).

Programs

  • Mathematica
    RealDigits[Log[3, 25], 10, 100][[1]]

Formula

Equals 2*A113209. - R. J. Mathar, Sep 08 2013
Previous Showing 11-19 of 19 results.