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 1-8 of 8 results.

A053510 Decimal expansion of log(Pi).

Original entry on oeis.org

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

Views

Author

Hsu, Po-Wei (Benny) (arsene_lupin(AT)intekom.co.za), Jan 14 2000

Keywords

Comments

Also the least positive x such that sin(exp(x))==0.
Also real part of log(log(-1)). - Stanislav Sykora, May 11 2015
Cheng, Dietel, Herblot, Huang, Krieger, Marques, Mason, Mereb, & Wilson show, expanding a remark by S. Lang, that Schanuel's conjecture implies that this constant and Pi are algebraically independent over a set E which includes the algebraic numbers and (in a technical sense) allows any finite number of exponentiations, see the paper for details and a still more general result. - Charles R Greathouse IV, Dec 15 2019

Examples

			1.1447298858494001741...
		

References

  • Wolfram Research, 1991 Mathematica Conference, Elementary Tutorial Notes, Section 1, Introduction to Mathematica, Paul Abbott, page 25.

Crossrefs

Programs

Formula

Equals log(log(-1)) - (Pi/2)*I. - Stanislav Sykora, May 11 2015
Equals 1 + Sum_{n>=1} zeta(2*n)/(n*(2*n+1)*2^(2*n)), where zeta is the Riemann zeta function. - Vaclav Kotesovec, Mar 04 2016
Equals 3/2 - Sum_{k>=1} (zeta(2*k)-1)/(k+1). - Vaclav Kotesovec, Jun 19 2021

Extensions

More terms from James Sellers, Jan 20 2000

A216582 Decimal expansion of the logarithm of Pi to base 2.

Original entry on oeis.org

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

Views

Author

Alonso del Arte, Sep 09 2012

Keywords

Examples

			1.651496129472318798...
		

References

  • Jörg Arndt and Christoph Haenel, Pi Unleashed, New York: Springer (2001), p. 239.

Crossrefs

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); Log(Pi(R))/Log(2); // G. C. Greubel, Apr 08 2019
  • Maple
    evalf(log[2](Pi)) ; # R. J. Mathar, Sep 11 2012
  • Mathematica
    RealDigits[Log[2, Pi], 10, 105][[1]]
  • PARI
    log(Pi)/log(2) \\ Michel Marcus, Mar 05 2019
    
  • Sage
    log(pi,2).n(digits=100) # Jani Melik, Oct 05 2012
    

Formula

Log_2(Pi) = log(Pi) / log(2) = A053510 / A002162.
Equals (A061444 / A002162) - 1 = (A094642 / A002162) + 1. - John W. Nicholson, Mar 12 2019

A219723 Numerators of convergents to log_10(Pi).

Original entry on oeis.org

0, 1, 87, 349, 436, 785, 1221, 5669, 296009, 597687, 893696, 48857271, 98608238, 936331413, 1034939651, 3006210715, 4041150366, 11088511447, 37306684707, 458768727931, 496075412638, 954844140569, 2405763693776, 5766371528121, 8172135221897
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 26 2012

Keywords

Examples

			0, 1/2, 87/175, 349/702, 436/877, 785/1579, 1221/2456, 5669/11403, ....
		

Crossrefs

Cf. A053511 (decimal), A219724 (denominators).

Programs

  • Mathematica
    Numerator@Convergents[Log[10, Pi], 25]

A219724 Denominators of convergents to log_10(Pi).

Original entry on oeis.org

1, 2, 175, 702, 877, 1579, 2456, 11403, 595412, 1202227, 1797639, 98274733, 198347105, 1883398678, 2081745783, 6046890244, 8128636027, 22304162298, 75041122921, 922797637350, 997838760271, 1920636397621, 4839111555513, 11598859508647, 16437971064160
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 26 2012

Keywords

Comments

Pi^a(n) gets increasingly close to 10^A219723(n).

Examples

			0, 1/2, 87/175, 349/702, 436/877, 785/1579, 1221/2456, 5669/11403, ....
		

Crossrefs

Cf. A053511 (decimal), A219723 (numerators).

Programs

  • Mathematica
    Denominator@Convergents[Log[10, Pi], 25]

A386725 a(n) is the nearest integer to n/log_10(Pi).

Original entry on oeis.org

0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129
Offset: 0

Views

Author

Stefano Spezia, Jul 31 2025

Keywords

Comments

Differs from A005843 for n > 43.
For n > 0, a(n) is the nonnegative integer such that abs(10^(n/a(n)) - Pi) is minimum.

Examples

			a(n) = 2*n corresponds to the Brahmagupta's approximation 10^(1/2) = sqrt(10) of Pi (cf. A010467).
		

Crossrefs

Programs

  • Mathematica
    a[n_]:=Round[n/Log10[Pi]]; Array[a,65,0]

Formula

a(n) = round(n/log10(Pi)).
a(n) >= 2*n.

A073365 Decimal expansion of log(log(Pi)).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Jul 29 2002

Keywords

Comments

Cheng, Dietel, Herblot, Huang, Krieger, Marques, Mason, Mereb, & Wilson show, expanding a remark by S. Lang, that Schanuel's conjecture implies that this constant and Pi are algebraically independent over a set E which includes the algebraic numbers and (in a technical sense) allows any finite number of exponentiations, see the paper for details and a still more general result. - Charles R Greathouse IV, Dec 16 2019

Examples

			0.13516870162052962769995812823...
		

Crossrefs

Cf. A000796 (Pi), A053510 (log(Pi)), A053511 (log_10(Pi)).

Programs

  • Mathematica
    RealDigits[Log[Log[Pi]],10,120][[1]] (* Harvey P. Dale, Mar 11 2017 *)
  • PARI
    log(log(Pi))

A235955 Decimal expansion of log_Pi 10.

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Jun 13 2014

Keywords

Examples

			= 2.01146586758806093876472204728870869669458302073723988728116...
		

Crossrefs

Cf. A053511.

Programs

  • Mathematica
    RealDigits[ Log[ Pi, 10], 10, 111]

Formula

A348960 a(n) = floor(log_10(Pi*n!)).

Original entry on oeis.org

0, 0, 0, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 20, 21, 22, 24, 25, 27, 28, 29, 31, 32, 34, 35, 37, 38, 40, 42, 43, 45, 46, 48, 50, 51, 53, 54, 56, 58, 59, 61, 63, 64, 66, 68, 70, 71, 73, 75, 77, 78, 80, 82, 84, 85, 87, 89, 91, 93, 95, 96, 98, 100
Offset: 0

Views

Author

Paul F. Marrero Romero, Nov 05 2021

Keywords

Crossrefs

Programs

Formula

a(n) = floor(log_10(Pi*n!)).
a(n) = floor(A053511 + log_10(n!)).
Showing 1-8 of 8 results.