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.

A256166 Decimal expansion of log(Gamma(1/4)).

Original entry on oeis.org

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

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Examples

			1.288022524698077457370610440219717295925377565112860...
		

Crossrefs

Cf. A068466 (Gamma(1/4)), A115252 (first Malmsten's integral).
Cf. decimal expansions of log(Gamma(1/k)): A155968 (k=2), A256165 (k=3), A256167 (k=5), A255888 (k=6), A256609 (k=7), A255306 (k=8), A256610 (k=9), A256612 (k=10), A256611 (k=11), A256066 (k=12), A256614 (k=16), A256615 (k=24), A256616 (k=48).

Programs

A256127 Decimal expansion of the second Malmsten integral: Integer_{x >= 1} log(log(x))/(1 + x + x^2) dx, negated.

Original entry on oeis.org

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

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Keywords

Examples

			-0.12632148170620903636522675325320239184424430946528...
		

Crossrefs

Cf. A115252 (first Malmsten integral), A256128 (third Malmsten integral) , A256129 (fourth Malmsten integral), A073005 (Gamma(1/3)), A256165 (log(Gamma(1/3))), A061444 (log(2*Pi)), A002391 (log 3), A002194 (sqrt 3).

Programs

  • Maple
    evalf(Pi*(8*log(2*Pi) - 3*log(3) - 12*log(GAMMA(1/3)))/(6*sqrt(3)),120); # Vaclav Kotesovec, Mar 17 2015
  • Mathematica
    RealDigits[Integrate[Log[Log[1/x]]/(1 + x + x^2), {x, 0, 1}], 10, 100][[1]] (* Alonso del Arte, Mar 16 2015 *)
    RealDigits[Pi*(8*Log[2*Pi] - 3*Log[3] - 12*Log[Gamma[1/3]])/(6*Sqrt[3]),10,105][[1]] (* Vaclav Kotesovec, Mar 17 2015 *)
  • PARI
    Pi*(8*log(2*Pi) - 3*log(3) - 12*log(gamma(1/3)))/(6*sqrt(3)) \\ Michel Marcus, Mar 18 2015
    
  • PARI
    intnum(x=0, 1, log(log(1/x))/(1 + x + x^2))
    
  • PARI
    intnum(x=1, oo, log(log(x))/(1 + x + x^2))
    
  • PARI
    intnum(x=0, [oo, 1], log(x)/(1 + 2*cosh(x))) \\ Gheorghe Coserea, Sep 26 2018

Formula

Equals Integral_{x=0..1} log(log(1/x))/(1 + x + x^2) dx.
Equals Integral_{x>=0} log(x)/(1 + 2*cosh(x)) dx.
Equals Pi*(8*log(2*Pi) - 3*log(3) - 12*log(Gamma(1/3)))/(6*sqrt(3)).

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

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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)).

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

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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.

A241017 Decimal expansion of Sierpiński's S constant, which appears in a series involving the function r(n), defined as the number of representations of the positive integer n as a sum of two squares. This S constant is the usual Sierpiński K constant divided by Pi.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Aug 08 2014

Keywords

Examples

			0.822825249678847032995328716261464949475693118894850218393815613...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 2.10 Sierpinski's Constant, p. 123.

Crossrefs

Programs

  • Mathematica
    S = Log[4*Pi^3*Exp[2*EulerGamma]/Gamma[1/4]^4]; RealDigits[S, 10, 104] // First
  • PARI
    log(agm(sqrt(2), 1)^2/2) + 2*Euler \\ Charles R Greathouse IV, Nov 26 2024

Formula

S = gamma + beta'(1) / beta(1), where beta is Dirichlet's beta function.
S = log(Pi^2*exp(2*gamma) / (2*L^2)), where L is Gauss' lemniscate constant.
S = log(4*Pi^3*exp(2*gamma) / Gamma(1/4)^4), where gamma is Euler's constant and Gamma is Euler's Gamma function.
S = A062089 / Pi, where A062089 is Sierpiński's K constant.
S = A086058 - 1, where A086058 is the conjectured (but erroneous!) value of Masser-Gramain 'delta' constant. [updated by Vaclav Kotesovec, Apr 27 2015]
S = 2*gamma + (4/Pi)*integral_{x>0} exp(-x)*log(x)/(1-exp(-2*x)) dx.
Sum_{k=1..n} r(k)/k = Pi*(log(n) + S) + O(n^(-1/2)).
Equals 2*A001620 - A088538*A115252 [Coffey]. - R. J. Mathar, Jan 15 2021

A257406 Decimal expansion of Integral_{0..infinity} log(x)/cosh(x) dx (negated).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Apr 22 2015

Keywords

Examples

			-0.5208856126019768910801877375794544390636383554462853499753755842...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(Pi/2)*Log[4*Pi^3/Gamma[1/4]^4], 10, 103] // First
    RealDigits[Integrate[-Log[x]/Cosh[x],{x,0,\[Infinity]}],10,120][[1]] (* Harvey P. Dale, Feb 05 2025 *)
  • PARI
    (Pi/2)*log(4*Pi^3/gamma(1/4)^4) \\ Michel Marcus, Apr 22 2015

Formula

(Pi/2)*log(4*Pi^3/Gamma(1/4)^4).
Also equals 2*Integral_{0..1} (1/(x^2+1))*log(log(1/x)) dx.
Also equals 2*Integral_{Pi/4..Pi/2} log(log(tan(x))) dx.
Showing 1-6 of 6 results.