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 1-7 of 7 results.

A154434 Decimal expansion of log_21 (13).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			.84248003091726510655878049884008339833348686470762097554384...

Links

Crossrefs

Cf. decimal expansion of log_21(m): A152825 (m=2), A153097 (m=3), A153131 (m=4), A153455 (m=5), A153611 (m=6), A153632 (m=7), A153895 (m=8), A154020 (m=9), A154171 (m=10), A154192 (m=11), A154213 (m=12), this sequence, A154499 (m=14), A154707 (m=15), A154839 (m=16), A154901 (m=17), A154977 (m=18), A155129 (m=19), A155532 (m=20), A155790 (m=22), A155909 (m=23), A156028 (m=24).

Programs

  • Mathematica
    RealDigits[Log[21, 13], 10, 100][[1]] (* Vincenzo Librandi, Sep 07 2013 *)

Formula

Equals A016636 / A016644. - R. J. Mathar, Jul 13 2025

A234518 Decimal expansion of log_12 (28/13).

Original entry on oeis.org

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

Views

Author

Jaroslav Krizek, Jan 03 2014

Keywords

Comments

Decimal expansion of maximal value of function alpha(n) = alpha-deviation from primality of number n = log_n(sigma(n)) - log_n(n+1) = log_n[sigma(n) / (n+1)] for n = 12, when alpha(12) = log_12(sigma(12)) - log_12(12+1) = log_12(28) - log_12(13) = log_12 (28/13) = 0,308766187…; alpha(p) = 0 for p = prime.

Examples

			0,3087661875664928997884010546628878661481631771557148…

Links

Crossrefs

Cf. A234515, A234516, A234517, A234519, A234520, A234521, A234522, A234523, A234524.

Programs

  • Mathematica
    RealDigits[Log[12,28/13],10,120][[1]] (* Harvey P. Dale, Apr 17 2022 *)
  • PARI
    log(28/13)/log(12) \\ Michel Marcus, Dec 11 2014

Formula

Decimal expansion of (A016651-A016636) / A016635.

A186503 Decimal expansion of the solution x to x^x = 13.

Original entry on oeis.org

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

Views

Author

Vladimir Joseph Stephan Orlovsky, Feb 22 2011

Keywords

Examples

			2.6410619164843958084118390040657912549308732...

Crossrefs

Cf. A016636, A030798, A173158, A000038, A173159, A173160, A173161, A173162, A173163, A090625, A186501, A186502, A186504, A344930, A093590.

Programs

  • Mathematica
    x=13;RealDigits[Log[x]/ProductLog[Log[x]],10,103][[1]]
RealDigits[x/.FindRoot[x^x==13,{x,2.6},WorkingPrecision->120],10,120][[1]] (* Harvey P. Dale, Feb 07 2025 *)

Formula

Equals log(13)/LambertW(log(13)). - Alois P. Heinz, Jun 16 2021

A016441 Continued fraction for log(13).

Original entry on oeis.org

2, 1, 1, 3, 2, 1, 6, 2, 1, 4, 47, 1, 1, 1, 1, 1, 11, 4, 2, 18, 1, 2, 2, 3, 1, 1, 2, 2, 3, 2, 40, 7, 1, 4, 1, 28, 6, 1, 2, 7, 1, 1, 1, 8, 1, 3, 1, 21, 1, 4, 1, 2, 4, 44, 3, 4, 4, 1, 3, 1, 23, 2, 2, 5, 1, 1, 33, 1, 1, 13, 1, 60, 115, 1, 2, 1
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Examples

			2.564949357461536736053487441... = 2 + 1/(1 + 1/(1 + 1/(3 + 1/(2 + ...)))). - _Harry J. Smith_, May 16 2009

Links

Crossrefs

Cf. A016636 (decimal expansion). - Harry J. Smith, May 16 2009

Programs

  • Mathematica
    ContinuedFraction[Log[13], 100] (* Paolo Xausa, Mar 22 2024 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 21000); x=contfrac(log(13)); for (n=1, 20000, write("b016441.txt", n, " ", x[n])); } \\ Harry J. Smith, May 16 2009

A016649 Decimal expansion of log(26).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane

Keywords

Examples

			3.258096538021482045470719563023495172880768079120462370539725520156858....

References

  • Milton Abramowitz and Irene A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 2.

Links

Crossrefs

Cf. A016454 (continued fraction).

Programs

  • Mathematica
    RealDigits[Log[26], 10, 100][[1]] (* Alonso del Arte, Apr 26 2015 *)
  • PARI
    default(realprecision, 20080); x=log(26); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b016649.txt", n, " ", d)); \\ Harry J. Smith, May 20 2009

Formula

Equals A002162 + A016636. - R. J. Mathar, Jul 22 2025

A016662 Decimal expansion of log(39).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane

Keywords

Examples

			3.663561646129646427448732678487844309452758502582956568153739844300958....

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 2.

Links

Crossrefs

Cf. A016467 (continued fraction).
Cf. A002391, A016636.

Programs

  • Maple
    Digits:=100: evalf(log(39)); # Wesley Ivan Hurt, Jan 27 2017
  • Mathematica
    RealDigits[Log[39], 10, 120][[1]] (* Vincenzo Librandi, Jun 21 2015 *)
  • PARI
    default(realprecision, 20080); x=log(39); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b016662.txt", n, " ", d)); \\ Harry J. Smith, May 21 2009

Formula

Equals A002391 + A016636. - Michel Marcus, Jan 27 2017

A016675 Decimal expansion of log(52).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane

Keywords

Examples

			3.951243718581427354887951684481671740956268213480717624660405529650251....

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 2.

Links

Crossrefs

Cf. A016480 (continued fraction).

Programs

  • Mathematica
    RealDigits[Log[52], 10, 120][[1]] (* Vincenzo Librandi, Jun 21 2015 *)
  • PARI
    default(realprecision, 20080); x=log(52); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b016675.txt", n, " ", d)); \\ Harry J. Smith, May 21 2009

Formula

Equals 2*A002162 + A016636. - R. J. Mathar, Jun 07 2024
Showing 1-7 of 7 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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