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 1-9 of 9 results.

A238181 Decimal expansion of sum_(n>=1) H(n)^2/n^3 where H(n) is the n-th harmonic number (Quadratic Euler Sum S(2,3)).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Feb 19 2014

Keywords

Examples

			1.6519427927044986239626937611144940161...
		

Crossrefs

Programs

  • Mathematica
    7/2*Zeta[5] - Zeta[2]*Zeta[3] // RealDigits[#, 10, 100]& // First
  • PARI
    7/2*zeta(5) - zeta(2)*zeta(3) \\ Stefano Spezia, May 22 2025

Formula

7/2*zeta(5) - zeta(2)*zeta(3).

A238183 Decimal expansion of sum_(n>=1) H(n)^2/n^7 where H(n) is the n-th harmonic number (Quadratic Euler Sum S(2,7)).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Feb 19 2014

Keywords

Examples

			1.019483497494382286206496675928126515...
		

Crossrefs

Programs

  • Mathematica
    Zeta[3]^3/3 - 5/2*Zeta[4]*Zeta[5] - 7/2*Zeta[3]*Zeta[6] - Zeta[2]*Zeta[7] + 55/6*Zeta[9] // RealDigits[#, 10, 100]& // First

Formula

zeta(3)^3/3-5/2*zeta(4)*zeta(5)-7/2*zeta(3)*zeta(6)-zeta(2)*zeta(7)+55/6*zeta(9).

A241215 Decimal expansion of Sum_{n>=1} H(n)^4/(n+1)^3 where H(n) is the n-th harmonic number.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Apr 17 2014

Keywords

Examples

			1.80161326804341290372948894202088843...
		

Crossrefs

Programs

  • Mathematica
    37/180*Pi^4*Zeta[3] - 5/6*Pi^2*Zeta[5] - 109/8*Zeta[7] // RealDigits[#, 10, 100]& // First
  • PARI
    37/2*zeta(3)*zeta(4) - 5*zeta(2)*zeta(5) - 109/8*zeta(7) \\ Stefano Spezia, Jan 19 2025

Formula

Equals (37/2)*zeta(3)*zeta(4) - 5*zeta(2)*zeta(5) - (109/8)*zeta(7).
Equals (37/180)*Pi^4*zeta(3) - (5/6)*Pi^2*zeta(5) - (109/8)*zeta(7).

A384457 Decimal expansion of Sum_{k>=1} H(k)^3/2^k, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, May 30 2025

Keywords

Examples

			3.59342794177494296025518240703339219591695480351933...
		

References

  • K. Ramachandra and R. Sitaramachandrarao, On series, integrals and continued fractions - II, Madras Univ. J., Sect. B, 51 (1988), pp. 181-198.

Crossrefs

Programs

  • Mathematica
    RealDigits[Zeta[3] + (Pi^2*Log[2] + Log[2]^3)/3, 10, 120][[1]]
  • PARI
    zeta(3) + (Pi^2*log(2) + log(2)^3)/3

Formula

Equals zeta(3) + (Pi^2*log(2) + log(2)^3)/3.

A384458 Decimal expansion of Sum_{k>=1} (-1)^(k+1)*H(k)^3/k, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, May 30 2025

Keywords

Examples

			0.27412574654925297067883303678750470762654489295575...
		

References

  • Ali Shadhar Olaikhan, An Introduction to the Harmonic Series and Logarithmic Integrals, 2021, p. 245, eq. (4.149).
  • K. Ramachandra and R. Sitaramachandrarao, On series, integrals and continued fractions - II, Madras Univ. J., Sect. B, 51 (1988), pp. 181-198.

Crossrefs

Programs

  • Mathematica
    RealDigits[(Pi*Log[2])^2/8 + 5*Zeta[4]/8 - 9*Zeta[3]*Log[2]/8 - Log[2]^4/4, 10, 120][[1]]
  • PARI
    (Pi*log(2))^2/8 + 5*zeta(4)/8 - 9*zeta(3)*log(2)/8 - log(2)^4/4

Formula

Equals (Pi*log(2))^2/8 + 5*zeta(4)/8 - 9*zeta(3)*log(2)/8 - log(2)^4/4.

A384459 Decimal expansion of Sum_{k>=1} (-1)^k*(3*k+1)*H(k)^3/2^k, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, May 30 2025

Keywords

Examples

			0.16440195389316542965263621650302311406441305151904...
		

References

  • K. Ramachandra and R. Sitaramachandrarao, On series, integrals and continued fractions - II, Madras Univ. J., Sect. B, 51 (1988), pp. 181-198.

Crossrefs

Programs

  • Mathematica
    RealDigits[Log[3/2]^2, 10, 120][[1]]
  • PARI
    log(3/2)^2

Formula

Equals A016578^2 = log(3/2)^2 (Ramachandra, 1981).
Equals Sum_{k>=1} (-1)^(k+1)*H(k)/((k+1)*2^k), where H(k) = A001008(k)/A002805(k) is the k-th harmonic number (Shamos, 2011).

A384460 Decimal expansion of Sum_{k>=1} (-1)^(k+1)*H(k)^2/k, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, May 30 2025

Keywords

Examples

			0.44246018937791249521879821917465633518413362702258...
		

References

  • Ovidiu Furdui, Limits, Series, and Fractional Part Integrals, Springer, 2013, section 3.4, p. 148.

Crossrefs

Programs

  • Mathematica
    RealDigits[(9*Zeta[3] + 4*Log[2]^3 - Pi^2*Log[2])/12, 10, 120][[1]]
  • PARI
    (9*zeta(3) + 4*log(2)^3 - Pi^2*log(2))/12

Formula

Equals (9*zeta(3) + 4*log(2)^3 - Pi^2*log(2))/12.

A384461 Decimal expansion of Sum_{k>=1} H(k)^4/k^2, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, May 30 2025

Keywords

Examples

			45.83394146541655719259576578914226334887951133154848...
		

References

  • Ali Shadhar Olaikhan, An Introduction to the Harmonic Series and Logarithmic Integrals, 2021, p. 230, eq. (4.122).

Crossrefs

Programs

  • Mathematica
    RealDigits[979*Zeta[6]/24 + 3*Zeta[3]^2, 10, 120][[1]]
  • PARI
    979*zeta(6)/24 + 3*zeta(3)^2

Formula

Equals 979*zeta(6)/24 + 3*zeta(3)^2.

A384462 Decimal expansion of Sum_{k>=1} H(k)^3/k^3, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, May 30 2025

Keywords

Examples

			2.30095455170052503980642276989225600046997564640623...
		

References

  • Ali Shadhar Olaikhan, An Introduction to the Harmonic Series and Logarithmic Integrals, 2021, p. 231, eq. (4.126).

Crossrefs

Programs

  • Mathematica
    RealDigits[93*Zeta[6]/16 - 5*Zeta[3]^2/2, 10, 120][[1]]
  • PARI
    93*zeta(6)/16 - 5*zeta(3)^2/2

Formula

Equals 93*zeta(6)/16 - 5*zeta(3)^2/2.
Showing 1-9 of 9 results.