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 1-3 of 3 results.

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

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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.

A335089 Decimal expansion of log(Pi^2/6).

Original entry on oeis.org

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

Views

Author

Terry D. Grant, Sep 11 2020

Keywords

Examples

			Equals 1/(2^2) + 1/(3^2) + (1/(4^2))*(1/2) + 1/(5^2) + + 1/(7^2) + (1/(8^2))*(1/3) + ... = 0.4977003024707...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Log[Pi^2/6], 10, 120][[1]]
    RealDigits[Sum[PrimeZetaP[2 k]/k, {k, 1, inf}], 10, 120][[1]]
  • PARI
    log(Pi^2/6) \\ Michel Marcus, Sep 15 2020

Formula

Equals Sum_{k>=2} MangoldtLambda(k) / ((k^2)*log(k)).
Equals Sum_{k>=1} (1/k)*(1/(A246655(n)^2)) where k is the exponent of the prime power, A025474(n+1).
Equals Sum_{k>=1} primezeta(2*k)/k.
Equals 2*log(Pi) - log(6).
Equals log(zeta(2)) = log(A013661).
Showing 1-3 of 3 results.