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 22 results. Next

A340576 Decimal expansion of Product_{primes p == 5 (mod 6)} 1/(1-1/p^2).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jan 12 2021

Keywords

Comments

The four similar sequences for products of primes mod 6 are these:
A175646 for Product_{primes p == 1 (mod 6)} 1/(1-1/p^2),
A340576 for Product_{primes p == 5 (mod 6)} 1/(1-1/p^2),
A340577 for Product_{primes p == 1 (mod 6)} 1/(1+1/p^2),
A340578 for Product_{primes p == 5 (mod 6)} 1/(1+1/p^2).

Examples

			1.06054829316911072817412636430987203493077130204487163127994372...
		

Crossrefs

Programs

  • Maple
    a := n -> 3^(2^(-n-2))*((1-3^(-2^(n+1)))/2)^(2^(-n-1)):
    b := n -> Zeta(n)/Im(polylog(n, (-1)^(2/3))):
    c := n -> a(n)*b(2^(n+1))^(1/2^(n+1)):
    Digits := 107: evalf((3/4)*mul(c(n), n=0..9)); # Peter Luschny, Jan 14 2021
  • Mathematica
    digits = 105;
    precision = digits + 10;
    prodeuler[p_, a_, b_, expr_] := Product[If[a <= p <= b, expr, 1], {p, Prime[Range[PrimePi[a], PrimePi[b]]]}];
    Lv3[s_] := prodeuler[p, 1, 2^(precision/s), 1/(1 - KroneckerSymbol[-3, p]*p^-s)] // N[#, precision] &;
    Lv4[s_] := 2*Im[PolyLog[s, Exp[2*I*Pi/3]]]/Sqrt[3];
    Lv[s_] := If[s >= 10000, Lv3[s], Lv4[s]];
    gv[s_] := (1 - 3^(-s))*Zeta[s]/Lv[s];
    pB = (3/4)*Product[gv[2^n*2]^(2^-(n+1)), {n, 0, 11}] // N[#, precision]&;
    RealDigits[pB, 10, digits][[1]] (* Most of this code is due to Artur Jasinski *)
    S[m_, n_, s_] := (t = 1; sums = 0; difs = 1; While[Abs[difs] > 10^(-digits - 5) || difs == 0, difs = (MoebiusMu[t]/t) * Log[If[s*t == 1, DirichletL[m, n, s*t], Sum[Zeta[s*t, j/m]*DirichletCharacter[m, n, j]^t, {j, 1, m}]/m^(s*t)]]; sums = sums + difs; t++]; sums);
    P[m_, n_, s_] := 1/EulerPhi[m] * Sum[Conjugate[DirichletCharacter[m, r, n]] * S[m, r, s], {r, 1, EulerPhi[m]}] + Sum[If[GCD[p, m] > 1 && Mod[p, m] == n, 1/p^s, 0], {p, 1, m}];
    Z[m_, n_, s_] := (w = 1; sumz = 0; difz = 1; While[Abs[difz] > 10^(-digits - 5), difz = P[m, n, s*w]/w; sumz = sumz + difz; w++]; Exp[sumz]);
    $MaxExtraPrecision = 1000; digits = 121; RealDigits[Chop[N[Z[6,5,2], digits]], 10, digits-1][[1]] (* Vaclav Kotesovec, Jan 15 2021 *)

Formula

g = A143298 = (9 - PolyGamma(1, 2/3) + PolyGamma(1, 4/3))/(4 sqrt(3));
h = A301429;
Equals (3*sqrt(3)*h^2)/2.
Equals (3/4)*A333240.
A340577 = Pi^4/(243*g*h^2);
A340578 = (45*g*h^2)/(2*Pi^2).
Equals Pi^2/(9*A175646). - Artur Jasinski, Jan 11 2021
Equals Sum_{k>=1} 1/A259548(k)^2. - Amiram Eldar, Jan 24 2021

A274416 Decimal expansion of V_3S, a Quantum Field Theory constant [negated] related to the coloring of the tetrahedron with three masses (star case).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 21 2016

Keywords

Examples

			-2.860862224139327350272784567773241917561441462020100039500166119667...
		

References

  • Jonathan Borwein and Peter Borwein, Experimental and Computational Mathematics: Selected Writings, Perfectly Scientific Press, 2010, p. 106.

Crossrefs

Cf. A274412 (V_1), A274413 (V_2A), A274414 (V_2N), A274415 (V_3T), A274417 (V_3L), A274418 (V_4A), A274419 (V_4N), A274420 (V_5), A274421 (V_6).

Programs

  • Mathematica
    C0 = A143298 = (9 - PolyGamma[1, 2/3] + PolyGamma[1, 4/3])/(4*Sqrt[3]);
    V3S = 6 Zeta[3] - 11/2 Zeta[4] - 4 C0^2;
    RealDigits[V3S, 10, 103][[1]]

Formula

V_3S = 6 zeta(3) - 11/2 zeta(4) - 4 C^2, where C is A143298.

A274417 Decimal expansion of V_3L, a Quantum Field Theory constant [negated] related to the coloring of the tetrahedron with three masses (line case).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 21 2016

Keywords

Examples

			-3.027009493987652019786374701758957286150741786417375620053670876...
		

References

  • Jonathan Borwein and Peter Borwein, Experimental and Computational Mathematics: Selected Writings, Perfectly Scientific Press, 2010, p. 106.

Crossrefs

Cf. A274412 (V_1), A274413 (V_2A), A274414 (V_2N), A274415 (V_3T), A274416 (V_3S), A274418 (V_4A), A274419 (V_4N), A274420 (V_5), A274421 (V_6).

Programs

  • Mathematica
    C0 = A143298 = (9 - PolyGamma[1, 2/3] + PolyGamma[1, 4/3])/(4*Sqrt[3]);
    V3L = 6 Zeta[3] - 15/4 Zeta[4] - 6 C0^2;
    RealDigits[V3L, 10, 102][[1]]
  • PARI
    clausen(n, x) = my(z = polylog(n, exp(I*x))); if (n%2, real(z), imag(z));
    6*(zeta(3) - (clausen(2, Pi/3)^2 + (zeta(2)/2)^2)) \\ Gheorghe Coserea, Sep 30 2018

Formula

V_3L = 6 zeta(3) - 15/4 zeta(4) - 6 C^2, where C is A143298.

A274418 Decimal expansion of V_4A, a Quantum Field Theory constant [negated] related to the coloring of the tetrahedron with four masses (adjacent case).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 21 2016

Keywords

Examples

			-5.9132047838840205304957178925354050268834109915339807072082741172...
		

References

  • Jonathan Borwein and Peter Borwein, Experimental and Computational Mathematics: Selected Writings, Perfectly Scientific Press, 2010, p. 106.

Crossrefs

Cf. A274412 (V_1), A274413 (V_2A), A274414 (V_2N), A274415 (V_3T), A274416 (V_3S), A274417 (V_3L), A274419 (V_4N), A274420 (V_5), A274421 (V_6).

Programs

  • Mathematica
    C0 = A143298 = (9 - PolyGamma[1, 2/3] + PolyGamma[1, 4/3])/(4*Sqrt[3]);
    V4A = 6 Zeta[3] - 77/12 Zeta[4] - 6 C0^2;
    RealDigits[V4A, 10, 100][[1]]

Formula

V_4A = 6 zeta(3) - 77/12 zeta(4) - 6 C^2, where C is A143298.

A274420 Decimal expansion of V_5, a Quantum Field Theory constant [negated] related to the coloring of the tetrahedron with five masses.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 21 2016

Keywords

Examples

			-8.21685981750873806291339833860108582496950833917257503683557579115...
		

References

  • Jonathan Borwein and Peter Borwein, Experimental and Computational Mathematics: Selected Writings, Perfectly Scientific Press, 2010, p. 106.

Crossrefs

Cf. A274412 (V_1), A274413 (V_2A), A274414 (V_2N), A274415 (V_3T), A274416 (V_3S), A274417 (V_3L), A274418 (V_4A), A274419 (V_4N), A274421 (V_6).

Programs

  • Mathematica
    digits = 101;
    C0 = A143298 = (9 - PolyGamma[1, 2/3] + PolyGamma[1, 4/3])/(4*Sqrt[3]);
    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"];
    V5 = 6 Zeta[3] - 469/27 Zeta[4] + 8/3 C0^2 - 16 V;
    RealDigits[V5, 10, digits][[1]]

Formula

V_5 = 6 zeta(3) - 469/27 zeta(4) + 8/3 C^2 - 16 V, where C is A143298 and V A274400.

A274421 Decimal expansion of V_6, a Quantum Field Theory constant [negated] related to the coloring of the tetrahedron with six masses.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 21 2016

Keywords

Examples

			-10.03527847976878917191470068515890023865033349600275134054452580...
		

References

  • Jonathan Borwein and Peter Borwein, Experimental and Computational Mathematics: Selected Writings, Perfectly Scientific Press, 2010, p. 106.

Crossrefs

Cf. A274412 (V_1), A274413 (V_2A), A274414 (V_2N), A274415 (V_3T), A274416 (V_3S), A274417 (V_3L), A274418 (V_4A), A274419 (V_4N), A274420 (V_5).

Programs

  • Mathematica
    C0 = A143298 = (9 - PolyGamma[1, 2/3] + PolyGamma[1, 4/3])/(4*Sqrt[3]);
    U = A255685 = Pi^4/180 + (Pi^2/12)*Log[2]^2 - (1/12)*Log[2]^4 - 2*PolyLog[4, 1/2];
    V6 = 6 Zeta[3] - 13 Zeta[4] - 8 U - 4 C0^2;
    RealDigits[V6, 10, 101][[1]]

Formula

V6 = 6 zeta(3) - 13 zeta(4) - 8 U - 4 C^2, where U is A255685 and C A143298.

A261024 Decimal expansion of Cl_2(2*Pi/3), where Cl_2 is the Clausen function of order 2.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Aug 07 2015

Keywords

Examples

			0.676627737606435750014135036183013523961126205020199861344992737851...
		

Crossrefs

Cf. A006752 (Cl_2(Pi/2) = Catalan's constant), A143298 (Cl_2(Pi/3) = Gieseking's constant), A261025 (Cl_2(Pi/4)), A261026 (Cl_2(3*Pi/4)), A261027 (Cl_2(Pi/6)), A261028 (Cl_2(5*Pi/6)).

Programs

  • Mathematica
    Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]); RealDigits[Cl2[2*Pi/3] // Re, 10, 105] // First
  • PARI
    clausen(n, x) = my(z = polylog(n, exp(I*x))); if (n%2, real(z), imag(z));
    clausen(2, 2*Pi/3) \\ Gheorghe Coserea, Sep 30 2018

Formula

Equals 2*Pi*log(G(2/3)/G(1/3)) - 2*Pi*LogGamma(1/3) + (2*Pi/3)*log(2*Pi/sqrt(3)), where G is the Barnes G function.

A261027 Decimal expansion of Cl_2(Pi/6), where Cl_2 is the Clausen function of order 2.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Aug 07 2015

Keywords

Examples

			0.8643791310538927496250363151902194786681885764036897041820...
		

Crossrefs

Cf. A006752 (Cl_2(Pi/2) = Catalan's constant), A143298 (Cl_2(Pi/3) = Gieseking's constant), A261024 (Cl_2(2*Pi/3)), A261025 (Cl_2(Pi/4)), A261026 (Cl_2(3*Pi/4)), A261028 (Cl_2(5*Pi/6)).

Programs

  • Mathematica
    Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]); RealDigits[Cl2[Pi/6] // Re, 10, 104] // First

Formula

Equals 2*Pi*log(G(11/12)/G(1/12)) - 2*Pi*LogGamma(1/12) + (Pi/6) * log(2*Pi*sqrt(2)/(sqrt(3)-1)), where G is the Barnes G function.

A261028 Decimal expansion of Cl_2(5*Pi/6), where Cl_2 is the Clausen function of order 2.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Aug 07 2015

Keywords

Examples

			0.356908327849065937114435038052959335697343922638539808173...
		

Crossrefs

Cf. A006752 (Cl_2(Pi/2) = Catalan's constant), A143298 (Cl_2(Pi/3) = Gieseking's constant), A261024 (Cl_2(2*Pi/3)), A261025 (Cl_2(Pi/4)), A261026 (Cl_2(3*Pi/4)), A261027 (Cl_2(Pi/6)).

Programs

  • Mathematica
    Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]); RealDigits[Cl2[5*Pi/6] // Re, 10, 104] // First

Formula

Equals 2*Pi*log(G(7/12)/G(5/12)) - 2*Pi*LogGamma(5/12) + (5*Pi/6) * log(2*Pi*sqrt(2)/(sqrt(3)+1)), where G is the Barnes G function.

A261025 Decimal expansion of Cl_2(Pi/4), where Cl_2 is the Clausen function of order 2.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Aug 07 2015

Keywords

Examples

			0.9818721510502033567179245430601956671307909716607304615766131...
		

Crossrefs

Cf. A006752 (Cl_2(Pi/2) = Catalan's constant), A143298 (Cl_2(Pi/3) = Gieseking's constant), A261024 (Cl_2(2*Pi/3)), A261026 (Cl_2(3*Pi/4)), A261027 (Cl_2(Pi/6)), A261028 (Cl_2(5*Pi/6)).

Programs

  • Mathematica
    Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]); RealDigits[Cl2[Pi/4] // Re, 10, 105] // First

Formula

Equals 2*Pi*log(G(7/8)/G(1/8)) - 2*Pi*LogGamma(1/8) + (Pi/4) * log(2*Pi/sqrt(2-sqrt(2))), where G is the Barnes G function.
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