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 1-4 of 4 results.

A274439 Decimal expansion of Q(1), value of one of five integrals related to Quantum Field Theory (see the paper by David Broadhurst).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 23 2016

Keywords

Examples

			2.636185725224872226546402047919868685533952437408546504962614340...
		

Crossrefs

Cf. A274439 (Q(1)), A274440 (Q(2)), A274441 (Q(3)), A274442 (Q(4)).

Programs

  • Mathematica
    Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]);
    Q[1] = 4/3 Cl2[Pi/3]^2 + 7/6 Zeta[4];
    RealDigits[N[Q[1], 103] // Chop][[1]]
  • PARI
    Q(n) = intnum(x=0, oo, acosh((x+2)/2)^2 * log((x+1)/x)/(x+n));
    Q(1) \\ Gheorghe Coserea, Sep 30 2018
    
  • PARI
    clausen(n, x) = my(z = polylog(n, exp(I*x))); if (n%2, real(z), imag(z));
    4/3*clausen(2, Pi/3)^2 + 7/6*zeta(4) \\ Gheorghe Coserea, Sep 30 2018

Formula

Q(n) = Integral_{x>0} arccosh((x+2)/2)^2 log((x+1)/x)/(x+n) dx.
Computation is done using the analytical form given by David Broadhurst:
Q(1) = (4/3)*Cl2(Pi/3)^2 + (7/6)*zeta(4), where Cl_2 is the Clausen integral.

A274440 Decimal expansion of Q(2), value of one of five integrals related to Quantum Field Theory (see the paper by David Broadhurst).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 23 2016

Keywords

Examples

			2.260399248120463689960929066240895031930761500163321388894889042329...
		

Crossrefs

Cf. A274438 (Q(0)), A274439 (Q(1)), A274441 (Q(3)), A274442 (Q(4)).

Programs

  • Mathematica
    Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]);
    U = A255685 = Pi^4/180 + (Pi^2/12)*Log[2]^2 - (1/12)*Log[2]^4 - 2*PolyLog[4, 1/2];
    Q[2] = -Cl2[Pi/3]^2 + 53/16 Zeta[4] + 5/2 U;
    RealDigits[N[Q[2], 104] // Chop][[1]]
  • PARI
    Q(n) = intnum(x=0, oo, acosh((x+2)/2)^2 * log((x+1)/x)/(x+n));
    Q(2) \\ Gheorghe Coserea, Sep 30 2018
    
  • PARI
    clausen(n, x) = my(z = polylog(n, exp(I*x))); if (n%2, real(z), imag(z));
    u31=Pi^4/180 + (Pi^2/12)*log(2)^2  - (1/12)*log(2)^4 - 2*polylog(4, 1/2);
    -clausen(2, Pi/3)^2 + 53/16*zeta(4) + 5/2*u31 \\ Gheorghe Coserea, Sep 30 2018

Formula

Q(n) = Integral_{x>0} arccosh((x+2)/2)^2 log((x+1)/x)/(x+n) dx.
Computation is done using the analytical form given by David Broadhurst:
Q(2) = -Cl2(Pi/3)^2 + 53/16 zeta(4) + 5/2 U, where Cl_2 is the Clausen integral and U is A255685.

A274442 Decimal expansion of Q(4), value of one of five integrals related to Quantum Field Theory (see the paper by David Broadhurst).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 23 2016

Keywords

Examples

			1.87447166949008260118095099948968029705739765892037953480769845119...
		

Crossrefs

Cf. A274438 (Q(0)), A274439 (Q(1)), A274440 (Q(2)), A274441 (Q(3)).

Programs

  • Mathematica
    digits = 101;
    U = A255685 = Pi^4/180 + (Pi^2/12)*Log[2]^2 - (1/12)*Log[2]^4 - 2*PolyLog[4, 1/2];
    v[k_] := ((-1)^k*((24*(k - 1)*(3*k - 4))/(3*k - 2)^3 + (8*(3*k*(3*k - 5) + 4))/(27*(k - 1)^3) + PolyGamma[2, (3*k)/2 - 1] - PolyGamma[2, (3*(k - 1))/2]))/(48*(k - 1)*(3*k - 4)*(3*k - 2));
    V = A274400 = 3 Zeta[3]/8 - 1/2 + NSum[v[k], {k, 2, Infinity}, WorkingPrecision -> digits + 10, Method -> "AlternatingSigns"];
    Q[4] = 125/54 Zeta[4] + 8 U - 8 V;
    RealDigits[Q[4], 10, digits][[1]]
  • PARI
    Q(n) = intnum(x=0, oo, acosh((x+2)/2)^2 * log((x+1)/x)/(x+n));
    Q(4) \\ Gheorghe Coserea, Sep 30 2018
    
  • PARI
    polygamma(n, x) = if (n == 0, psi(x), (-1)^(n+1)*n!*zetahurwitz(n+1, x));
    u31=Pi^4/180 + (Pi^2/12)*log(2)^2  - (1/12)*log(2)^4 - 2*polylog(4, 1/2);
    v31=3*zeta(3)/8 - 1/2 + sumalt(k=2, (-1)^k*((24*(k-1)*(3*k-4))/(3*k-2)^3 + (8*(3*k*(3*k-5)+4))/(27*(k-1)^3) + polygamma(2, (3*k)/2-1) - polygamma(2, (3*(k-1))/2))/(48*(k-1)*(3*k-4)*(3*k-2)));
    125/54*zeta(4) + 8*u31 - 8*v31 \\ Gheorghe Coserea, Sep 30 2018

Formula

Q(n) = Integral_{0..inf} arccosh((x+2)/2)^2 log((x+1)/x)/(x+n) dx.
Computation is done using the analytical form given by David Broadhurst:
Q(4) = 125/54 zeta(4) + 8 U - 8 V, where U is A255685 and V A274400.

A274438 Decimal expansion of Q(0), value of one of five integrals related to Quantum Field Theory (see the paper by David Broadhurst).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 23 2016

Keywords

Examples

			4.1204258576856330093331932058655183968902289805100953379974262667755...
		

Crossrefs

Cf. A274439 (Q(1)), A274440 (Q(2)), A274441 (Q(3)), A274442 (Q(4)).

Programs

  • Mathematica
    Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]);
    Q[0] = 4 Cl2[Pi/3]^2 ;
    RealDigits[N[Q[0], 104] // Chop][[1]]
  • PARI
    Q(n) = intnum(x=0, oo, acosh((x+2)/2)^2 * log((x+1)/x)/(x+n));
    Q(0) \\ Gheorghe Coserea, Oct 01 2018
    
  • PARI
    clausen(n, x) = my(z = polylog(n, exp(I*x))); if (n%2, real(z), imag(z));
    4*clausen(2, Pi/3)^2 \\ Gheorghe Coserea, Oct 01 2018

Formula

Q(n) = Integral_{0..inf} arccosh((x+2)/2)^2 log((x+1)/x)/(x+n) dx.
Computation is done using the analytical form given by David Broadhurst: Q(0) = 4 Cl_2(Pi/3)^2, where Cl_2 is the Clausen integral.
15 Q(0) + 144 Q(1) - 448 Q(2) + 126 Q(3) + 168 Q(4) = 0.
Showing 1-4 of 4 results.