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 1-6 of 6 results.

A104139 Decimal expansion of log_10(9).

Original entry on oeis.org

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

Views

Author

Lekraj Beedassy, Mar 07 2005

Keywords

Examples

			log_10(9) = 0.95424250943932487459005580651...
		

Crossrefs

Cf. decimal expansion of log_10(m): A007524 (m = 2), A114490 (m = 3), A114493 (m = 4), A153268 (m = 5), A153496 (m = 6), A153620 (m = 7), A153790 (m = 8), this sequence, A154182 (m = 11), A154203 (m = 12), A154368 (m = 13), A154478 (m = 14), A154580 (m = 15), A154794 (m = 16), A154860 (m = 17), A154953 (m = 18), A155062 (m = 19), A155522 (m = 20), A155677 (m = 21), A155746 (m = 22), A155830 (m = 23), A155979 (m = 24).

Programs

Formula

Equals A016632 / A002392 . - R. J. Mathar, Mar 11 2008

Extensions

More terms from Stefan Steinerberger, Mar 14 2006
More terms from R. J. Mathar, Mar 11 2008

A154009 Decimal expansion of log_6 (9).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			1.2262943855309168262595077230643582470697162810857931432210...
		

Crossrefs

Cf. decimal expansion of log_6(m): A152683 (m=2), A152935 (m=3), A153102 (m=4), A153202 (m=5), A153617 (m=7), A153754 (m=8), this sequence, A154157 (m=10), A154178 (m=11), A154199 (m=12), A154278 (m=13), A154466 (m=14), A154567 (m=15), A154776 (m=16), A154856 (m=17), A154911 (m=18), A155044 (m=19), A155490 (m=20), A155554 (m=21), A155697 (m=22), A155823 (m=23), A155959 (m=24).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); Log(9)/Log(6); // G. C. Greubel, Sep 14 2018
  • Mathematica
    RealDigits[Log[6, 9], 10, 100][[1]] (* Vincenzo Librandi, Aug 31 2013 *)
  • PARI
    default(realprecision, 100); log(9)/log(6) \\ G. C. Greubel, Sep 14 2018
    

Formula

Equals A016632 / A016629 =2/(1+A102525). - R. J. Mathar, Jul 29 2024

A338155 (Smallest prime >= 3^n) - (largest prime <= 3^n).

Original entry on oeis.org

0, 4, 6, 4, 10, 6, 24, 10, 6, 22, 36, 74, 30, 10, 18, 124, 44, 20, 70, 16, 60, 6, 52, 30, 34, 22, 42, 48, 144, 30, 20, 104, 122, 90, 50, 12, 52, 18, 140, 156, 72, 126, 126, 42, 68, 90, 98, 100, 66, 74, 50, 174, 30, 38, 126, 72, 30, 378, 102, 176, 108, 130
Offset: 1

Views

Author

A.H.M. Smeets, Oct 25 2020

Keywords

Comments

Size of prime gap containing the number 3^n, for n > 1.
From Gauss's prime counting function approximation, the expected gap size should be approximately n*log(3), however, the observed values seem to be closer to n*log(8.72) ~ n*log(3^2) = n*A016632.

Crossrefs

Cf. A058249 (for 2^n), A338419 (for 5^n), A338376 (for 6^n), A038804 (for 10^n).

Programs

  • Mathematica
    a[1] = 0; a[n_] := First @ Differences @ NextPrime[3^n, {-1, 1}]; Array[a, 60] (* Amiram Eldar, Oct 30 2020 *)
  • PARI
    a(n) = if (n==1, 0, nextprime(3^n) - precprime(3^n)); \\ Michel Marcus, Oct 25 2020

Formula

a(n) = A013598(n) + A013604(n) for n > 1.

A016704 Decimal expansion of log(81).

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			4.394449154672438765580980947690102818589962231290997806938777334549977....
		

Crossrefs

Cf. A016509 (continued fraction).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); Log(81); // G. C. Greubel, Sep 17 2018
  • Mathematica
    RealDigits[Log[81],10,120][[1]] (* Harvey P. Dale, Feb 20 2012 *)
  • PARI
    default(realprecision, 20080); x=log(81); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b016704.txt", n, " ", d)); \\ Harry J. Smith, May 24 2009
    

Formula

2 times A016632.

A016737 Continued fraction for log(9).

Original entry on oeis.org

2, 5, 14, 4, 1, 2, 2, 8, 1, 15, 1, 2, 1, 8, 2, 7, 1, 3, 3, 1, 1, 1, 2, 17, 1, 4, 2, 1, 2, 6, 1, 2, 2, 5, 1, 1, 2, 2, 1, 1, 1, 27, 3, 3, 4, 1, 1, 306, 2, 1, 1, 2, 3, 1, 1, 4, 5, 1, 1, 38, 1, 4, 1, 6, 1, 11, 10, 1, 9, 10, 2, 5, 2, 1, 3, 8, 1, 2, 3, 6, 1, 4, 2, 3
Offset: 0

Views

Author

Keywords

Examples

			2.19722457733621938279049047... = 2 + 1/(5 + 1/(14 + 1/(4 + 1/(1 + ...)))). - _Harry J. Smith_, May 16 2009
		

Crossrefs

Cf. A016632 (decimal expansion).

Programs

  • Magma
    ContinuedFraction(2*Log(3)); // G. C. Greubel, Sep 15 2018
  • Mathematica
    ContinuedFraction[Log[9],120] (* Harvey P. Dale, May 21 2017 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 21000); x=contfrac(log(9)); for (n=1, 20000, write("b016737.txt", n-1, " ", x[n])); } \\ Harry J. Smith, May 16 2009
    

Extensions

Offset changed by Andrew Howroyd, Jul 10 2024

A387247 Decimal expansion of (2*log(3) + 7)/8.

Original entry on oeis.org

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

Views

Author

Stefano Spezia, Aug 24 2025

Keywords

Examples

			1.149653072167027422848811309230631426161872639...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(2Log[3]+7)/8,10,100][[1]]
Showing 1-6 of 6 results.