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 1-10 of 46 results. Next

A061444 Decimal expansion of log(2 * Pi).

Original entry on oeis.org

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

Views

Author

Frank Ellermann, Jun 11 2001

Keywords

Comments

Used in formulas for gamma(x), e.g., in Stirling's approximation for m!.
Also decimal expansion of zeta'(0)/zeta(0). - Benoit Cloitre, Sep 28 2002
The value of log(2*Pi) is close to 1 + Sum_{n>=2} log(zeta(n)) = 1.83067035427178011248.... - Arkadiusz Wesolowski, Jul 17 2011

Examples

			1.837877066409345483560659472811235279722794947275566825634303...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[Log[2*Pi], 100]][[1]] (* Arkadiusz Wesolowski, Aug 29 2011 *)
  • PARI
    { default(realprecision, 20080); x=log(2*Pi); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b061444.txt", n, " ", d)) } \\ Harry J. Smith, Jul 22 2009

Formula

Equals A002162 + A053510 = A131659 - A094642. - R. J. Mathar, Aug 27 2011
Equals 1 + Sum_{k>=1} zeta(2*k)/(k*(2*k + 1)). - Amiram Eldar, Aug 20 2020

A155968 Decimal expansion of (1/2)*log(Pi).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jan 31 2009

Keywords

Comments

This sequence is also the decimal expansion of the logarithm of the Gamma-function at 1/2. - Iaroslav V. Blagouchine, Mar 20 2015

Examples

			0.572364942924700087071713675676529355823...
		

Crossrefs

Cf. A053510.

Programs

  • Maple
    evalf(log(Pi)/2);
  • Mathematica
    RealDigits[Log[Pi]/2,10,120][[1]] (* Harvey P. Dale, May 31 2015 *)
  • PARI
    log(gamma(1/2)) \\ or \\ log(Pi)/2 \\ G. C. Greubel, Jan 16 2017

Formula

Equals A053510/2 = log(A002161) = A131659/4.

A094642 Decimal expansion of log(Pi/2).

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			log(Pi/2) = 0.45158270528945486472619522989488214357179467855505...
		

References

  • George Boros and Victor Moll, Irresistible Integrals: Symbolics, Analysis and Experiments in the Evaluation of Integrals, Cambridge University Press, Cambridge, 2004, Chap. 7.
  • Jonathan Borwein and Peter Borwein, Pi and the AGM, John Wiley & Sons, New York, 1987, Chap. 11.
  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.6.3, pp. 43-44.

Crossrefs

Programs

Formula

Equals Sum_{n>=1} zeta(2*n)/(n*2^(2*n)) (cf. Boros & Moll p. 131). - Jean-François Alcover, Apr 29 2013
Equals Re(log(log(I))). - Stanislav Sykora, May 09 2015
Equals Integral_{-oo..+oo} -log(1/2 + i*z)/cosh(Pi*z) dz, where i is the imaginary unit. - Peter Luschny, Apr 08 2018
Equals Integral_{0..Pi/2} (2/(Pi-2*t)-tan(t)) dt. - Clark Kimberling, Jul 10 2020
Equals -Sum_{k>=1} log(1 - 1/(2*k)^2). - Amiram Eldar, Aug 12 2020
Equals Sum_{k>=1} (-1)^(k+1) * log(1 + 1/k). - Amiram Eldar, Jun 26 2021
Equals A053510 - A002162. - R. J. Mathar, Jun 15 2023

A053511 Decimal expansion of log_10 (Pi).

Original entry on oeis.org

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

Views

Author

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

Keywords

Examples

			0.49714987269413385435126828829089887365167832438...
		

Crossrefs

Cf. A053510 (log(Pi)), A002392 (log(10)).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); Log(10, Pi(R)); // G. C. Greubel, May 15 2019
    
  • Mathematica
    RealDigits[Log[10, Pi], 10, 105][[1]] (* Alonso del Arte, Sep 05 2012 *)
  • PARI
    log(Pi)/log(10) \\ Charles R Greathouse IV, Sep 05 2012
    
  • Sage
    numerical_approx(log(pi, 10), digits=100) # G. C. Greubel, May 15 2019

Extensions

More terms from James Sellers, Jan 20 2000

A115252 Decimal expansion of -(Pi*log((sqrt(2*Pi)*Gamma(3/4))/Gamma(1/4)))/2.

Original entry on oeis.org

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

Views

Author

Eric W. Weisstein, Jan 17 2006

Keywords

Comments

This sequence (its negated version) is also the decimal expansion of the first Malmsten integral int_{x=1..infinity} log(log(x))/(1 + x^2) dx = int_{x=0..1} log(log(1/x))/(1 + x^2) dx = int_{x=0..infinity} 0.5*log(x)/cosh(x) dx = int_{x=Pi/4..Pi/2} log(log(tan(x))) dx = (1/2)*Pi*log(2) + (3/4)*Pi*log(Pi) - Pi*log(Gamma(1/4)). - Iaroslav V. Blagouchine, Mar 29 2015

Examples

			0.26044280630098844554009386878972721953181917772314...
		

Crossrefs

Cf. A256127 (second Malmsten integral), A256128 (third Malmsten integral), A256129 (fourth Malmsten integral), A068466 (Gamma(1/4)), A256166 (log(Gamma(1/4))), A002162 (log 2), A053510 (log Pi).

Programs

  • Mathematica
    RealDigits[-Pi/2*Log[Sqrt[2 Pi] Gamma[3/4]/Gamma[1/4]], 10, 111][[1]] (* Robert G. Wilson v, Dec 06 2014 *)
  • PARI
    (-Pi*log((sqrt(2*Pi)*gamma(3/4))/gamma(1/4)))/2 \\ Michel Marcus, Dec 06 2014

Formula

Equals integral_[0..1] log(1/log(1/x))/(1+x^2) dx. - Jean-François Alcover, Jan 28 2015

A059561 Beatty sequence for log(Pi).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77, 78, 80, 81
Offset: 1

Views

Author

Mitch Harris, Jan 22 2001

Keywords

Comments

a(n) is the largest integer m such that e^m < Pi^n. - Stanislav Sykora, May 29 2015

Crossrefs

Beatty complement is A059562.
Cf. A000796 (Pi), A001113 (e), A053510 (log(Pi)).
Cf. A022932 (characteristic function).

Programs

  • Mathematica
    Floor[Range[100]*Log[Pi]] (* Paolo Xausa, Jul 05 2024 *)
  • PARI
    { default(realprecision, 100); b=log(Pi); for (n = 1, 2000, write("b059561.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009

Formula

a(n) = A004777(n+1), 1 <= n < 83. - R. J. Mathar, Oct 05 2008
a(n) = floor(n*log(Pi)). - Michel Marcus, Jan 04 2015

A231736 Decimal expansion of the natural logarithm of Pi^Pi.

Original entry on oeis.org

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

Views

Author

Stanislav Sykora, Nov 13 2013

Keywords

Examples

			3.59627499972915819808600175164636038136917928975387723049724412082...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Pi * Log[Pi], 10, 120][[1]] (* Amiram Eldar, May 17 2023 *)
  • PARI
    Pi*log(Pi)

Formula

Equals Pi*log(Pi).

A256128 Decimal expansion of the third Malmsten integral: int_{x=1..infinity} log(log(x))/(1 - x + x^2) dx, negated.

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			-0.671719601885874542354405069288779884008802066219356...
		

Crossrefs

Cf. A115252 (first Malmsten integral), A256127 (second Malmsten integral), A256129 (fourth Malmsten integral), A073005 (Gamma(1/3)), A002162 (log 2), A002391 (log 3), A053510 (log Pi), A002194 (sqrt 3).

Programs

  • Maple
    evalf(Pi*(7*log(2)+8*log(Pi)-3*log(3)-12*log(GAMMA(1/3)))/(3*sqrt(3)),120); # Vaclav Kotesovec, Mar 17 2015
  • Mathematica
    RealDigits[Pi*(7*Log[2]+8*Log[Pi]-3*Log[3]-12*Log[Gamma[1/3]])/(3*Sqrt[3]),10,105][[1]] (* Vaclav Kotesovec, Mar 17 2015 *)
  • PARI
    Pi*(7*log(2)+8*log(Pi)-3*log(3)-12*log(gamma(1/3)))/(3*sqrt(3)) \\ Michel Marcus, Mar 18 2015

Formula

Equals integral_{x=0..1} log(log(1/x))/(1 - x + x^2) dx.
Equals integral_{x=0..infinity} log(x)/(1 - 2*cosh(x)) dx.
Equals Pi*(7*log(2) + 8*log(Pi) - 3*log(3) - 12*log(Gamma(1/3)))/(3*sqrt(3)).

A231737 Decimal expansion of the natural logarithm of Pi^(1/Pi).

Original entry on oeis.org

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

Views

Author

Stanislav Sykora, Nov 13 2013

Keywords

Examples

			0.3643788396759062570495877303161624138917070390986055504746692...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Log[Pi]/Pi, 10, 120][[1]] (* Amiram Eldar, May 17 2023 *)
  • PARI
    log(Pi)/Pi

Formula

Equals log(Pi)/Pi.

A256129 Decimal expansion of the fourth Malmsten integral: int_{x=1..infinity} log(log(x))/(1 + x)^2 dx, negated.

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			-0.0628164798060389979401584300937601437351823286924336...
		

Crossrefs

A115252 (first Malmsten integral), A256127 (second Malmsten integral), A256128 (third Malmsten integral), A002162 (log 2), A053510 (log Pi), A001620 (Euler's constant, gamma).

Programs

  • Maple
    evalf((log(Pi/2)-gamma)/2,120); # Vaclav Kotesovec, Mar 17 2015
  • Mathematica
    RealDigits[(Log[Pi/2]-EulerGamma)/2,10,105][[1]] (* Vaclav Kotesovec, Mar 17 2015 *)
  • PARI
    (-Euler+log(Pi)-log(2))/2 \\ Michel Marcus, Mar 18 2015

Formula

Equals integral_{x=0..1} log(log(1/x))/(1 + x)^2 dx.
Equals integral_{x=0..infinity} 0.5*log(x)/(1 + cosh(x)) dx.
Equals (log(Pi) - log(2) - gamma)/2.
Showing 1-10 of 46 results. Next