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 12 results. Next

A256778 Decimal expansion of the generalized Euler constant gamma(1,4).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Apr 10 2015

Keywords

Examples

			0.71028979306409369731376647579508261030406104249693294...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.5.3, p. 32.

Crossrefs

Cf. A001620 (EulerGamma), A016627, A020777, A228725 (gamma(1,2)), A256425 (gamma(1,3)), A256779-A256784 (selection of ruler-and-compass constructible gamma(r,k)).

Programs

  • Magma
    R:=RealField(100); (2*EulerGamma(R) + Pi(R) + 2*Log(2))/8; // G. C. Greubel, Aug 27 2018
  • Mathematica
    RealDigits[EulerGamma/4 + Pi/8 + Log[2]/4, 10, 103] // First
  • PARI
    default(realprecision, 100); (2*Euler + Pi + 2*log(2))/8 \\ G. C. Greubel, Aug 27 2018
    

Formula

Equals (2*EulerGamma + Pi + 2*log(2))/8.
Equals Sum_{n>=0} (1/(4n+1) - 1/2*arctanh(2/(4n+3))).
Equals -(psi(1/4) + log(4))/4 = (A020777 - A016627)/4. - Amiram Eldar, Jan 07 2024

A332645 Decimal expansion of Sum_{n>=1} 1/z(n)^2 where z(n) is the imaginary part of the n-th nontrivial zero of the Riemann zeta function.

Original entry on oeis.org

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

Views

Author

Artur Jasinski, Feb 18 2020

Keywords

Examples

			0.0231049931154189707889338104303390140033817603974220901231825...
		

References

  • J. P. Gram, "Note sur le calcul de la fonction zeta(s) de Riemann", Det Kgl. Danske Vid. Selsk. Overs., 1895, pp. 303-308. p.307 (16 decimal digits).
  • Charles Jean De La Vallée Poussin, Sur La Fonction de Riemann Et Le Nombre Des Nombres Premiers Inférieurs à Une Limite Donnee, 1899.

Crossrefs

Programs

  • Maple
    evalf((-32 - log(Pi)^2 + Psi(0, 1/4)^2 + Psi(1, 1/4) + 4*(Psi(0, 1/4) * Zeta(1, 1/2) + Zeta(2, 1/2)) / Zeta(1/2)) / 8, 120); # Vaclav Kotesovec, Feb 19 2020
  • Mathematica
    Join[{0}, RealDigits[N[-4 + Catalan + Pi^2/8 + (Zeta''[1/2]/Zeta[1/2] - (Zeta'[1/2] / Zeta[1/2])^2)/2, 105]][[1]]]
    N[SeriesCoefficient[Log[s*(s-1)*Pi^(-s/2)*Gamma[s/2]*Zeta[s]/2], {s, 1/2, 2}], 105] (* Vaclav Kotesovec, Feb 19 2020 *)

Formula

Equals -4 + G + Pi^2/8 + (1/2)(zeta''(1/2)/zeta(1/2) - (zeta'(1/2)/zeta(1/2))^2) where G is the Catalan constant A006752.
Equals G - 4 + (Pi^2 - (gamma + Pi/2 + log(8*Pi))^2) / 8 + zeta''(1/2) / (2*zeta(1/2)), where gamma is the Euler-Mascheroni constant A001620 and G is the Catalan constant A006752. - Vaclav Kotesovec, Feb 19 2020
Also equals (-32 - log(Pi)^2 + psi(0, 1/4)^2 + psi(1, 1/4) + 4*(psi(0, 1/4) * zeta'(1/2) + zeta''(1/2)) / zeta(1/2)) / 8, where psi(0, 1/4) = -A020777 and psi(1, 1/4) = A282823. - Vaclav Kotesovec, Feb 19 2020

A200134 Decimal expansion of the negated value of the digamma function at 3/4.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Nov 13 2011

Keywords

Examples

			Psi(3/4) = -1.085860879786472169626886762817...
		

Crossrefs

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); -EulerGamma(R) + Pi(R)/2 - 3*Log(2); // G. C. Greubel, Aug 29 2018
  • Maple
    evalf(-gamma+Pi/2-3*log(2)) ;
  • Mathematica
    RealDigits[ -PolyGamma[3/4], 10, 97] // First (* Jean-François Alcover, Feb 20 2013 *)
    N[StieltjesGamma[0, 3/4], 99] (* Peter Luschny, May 16 2018 *)
  • PARI
    -psi(3/4) \\ Charles R Greathouse IV, Nov 22 2011
    

Formula

Psi(3/4) = -gamma + Pi/2 - 3*log(2) = A000796 - A020777 = 3.14159... - 4.22745...
Pi = gamma(0,1/4) - gamma(0,3/4) = A020777 - A200134, where gamma(n,x) denotes the generalized Stieltjes constants. - Peter Luschny, May 16 2018

A200135 Decimal expansion of the negated value of the digamma function at 1/5.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Nov 13 2011

Keywords

Examples

			Psi(1/5) =  -5.289039896592188295547207962...
		

Crossrefs

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); -EulerGamma(R) -Pi(R)*Sqrt(1+2/Sqrt(5))/2 -5*Log(5)/4 -Sqrt(5)/4*Log((3+Sqrt(5)/2) ); // G. C. Greubel, Sep 03 2018
  • Maple
    -gamma-Pi*sqrt(1+2/sqrt(5))/2-5*log(5)/4-sqrt(5)/4*log((3+sqrt(5)/2) ); evalf(%) ;
  • Mathematica
    RealDigits[-PolyGamma[1/5], 10, 105] // First (* Jean-François Alcover, Feb 11 2013 *)
  • PARI
    -psi(1/5) \\ Charles R Greathouse IV, Jul 19 2013
    

Formula

Psi(1/5) = -gamma - Pi*sqrt(1 + 2/sqrt(5))/2 - 5*log(5)/4 -sqrt(5)*log((3 + sqrt(5))/2)/4 where gamma = A001620, sqrt(1 + 2/sqrt(5)) = A019952, (3 + sqrt(5))/2 = A104457.

Extensions

More terms from Jean-François Alcover, Feb 11 2013

A200064 Decimal expansion of the negated value of the digamma function at 2/3.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Nov 13 2011

Keywords

Examples

			psi(2/3) = -1.3182344157865884724023408166...
		

Crossrefs

Programs

Formula

psi(2/3) = -gamma+Pi*sqrt(3)/6-3*log(3)/2 = A093602 - A047787 = 1.813799 -3.132033...

A200138 Decimal expansion of the negated value of the digamma function at 4/5.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Nov 13 2011

Keywords

Examples

			Psi(4/5) = -0.965008566706138459391297633...
		

Crossrefs

Programs

  • Maple
    -gamma+Pi*sqrt(1+2/sqrt(5))/2-5*log(5)/4-sqrt(5)/4*log(3/2+sqrt(5)/2) ; evalf(%) ;
  • Mathematica
    RealDigits[ -PolyGamma[4/5], 10, 87] // First (* Jean-François Alcover, Feb 20 2013 *)
  • PARI
    -psi(4/5) \\ Charles R Greathouse IV, Nov 22 2011

Formula

Psi(4/5) = -gamma + Pi*sqrt(1+2/sqrt 5)/2 -5*log(5)*log((3+sqrt 5)/2)/4.

A250129 Decimal expansion of the negated value of the digamma function at 1/8.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jan 15 2015

Keywords

Examples

			Psi(1/8) = -8.388492663295854867802742923086343000051446...
		

Crossrefs

Programs

Formula

Psi(1/8) = -gamma - (1/2)*(1+sqrt(2))*Pi - sqrt(2)*arccoth(sqrt(2)) - 4*log(2).

A306716 Decimal expansion of the negated value of the digamma function at 1/10.

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Aug 22 2019

Keywords

Examples

			Equals 10.4237549404110767951682162190100254042916425624441889203263920841...
		

Crossrefs

Programs

  • Maple
    evalf(-Psi(1/10), 102);
  • Mathematica
    RealDigits[-PolyGamma[1/10], 10, 105][[1]]
  • PARI
    -psi(1/10)

Formula

Psi(1/10) = -gamma - Pi*5^(1/4)*(sqrt(2 + sqrt(5))/2) - 2*log(2) - 5*log(5)/4 - 3*sqrt(5)*log((1 + sqrt(5))/2)/2, where gamma is the Euler-Mascheroni constant A001620.
Equals gamma - H(-9/10), H(z) the harmonic number. - Peter Luschny, Aug 22 2019

A200136 Decimal expansion of the negated value of the digamma function at 2/5.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Nov 13 2011

Keywords

Examples

			Psi(2/5) = -2.5613845445851161457306754820475...
		

Crossrefs

Programs

  • Maple
    -gamma-Pi*sqrt(1-2/sqrt(5))/2-5*log(5)/4+sqrt(5)*log((3+sqrt(5))/2)/4 ; evalf(%) ;
  • Mathematica
    RealDigits[ PolyGamma[2/5], 10, 84] // First (* Jean-François Alcover, Feb 21 2013 *)
  • PARI
    -psi(2/5) \\ Charles R Greathouse IV, Jul 19 2013

Formula

Psi(2/5) = -gamma -Pi*sqrt(1-2/sqrt 5)/2 -5*log(5)/4 +sqrt(5)*log((3+sqrt 5)/2)/4.

A200137 Decimal expansion of the negated digamma function at 3/5.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Nov 13 2011

Keywords

Examples

			Psi(3/5) = -1.540619213893190414760663948806231941510...
		

Crossrefs

Programs

  • Maple
    -gamma+Pi*sqrt(1-2/sqrt(5))/2-5*log(5)/4+sqrt(5)/4*log(3/2+sqrt(5)/2) ; evalf(%) ;
  • Mathematica
    RealDigits[-PolyGamma[3/5], 10, 105] // First (* Jean-François Alcover, Feb 11 2013 *)
  • PARI
    -psi(3/5) \\ Charles R Greathouse IV, Jul 19 2013

Formula

Psi(3/5) = -gamma +Pi*sqrt( 1-2/sqrt 5)/2 -5*log(5)/4 +sqrt(5)*log((3+sqrt 5)/2)/4.

Extensions

More terms from Jean-François Alcover, Feb 11 2013
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