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 27 results. Next

A233090 Decimal expansion of Sum_{n>=1} (-1)^(n-1)*H(n)/n^2, where H(n) is the n-th harmonic number.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Dec 04 2013, after the comment by Peter Bala about A233033

Keywords

Examples

			0.7512855644747464283748363509446562442281164327128118011201697220886...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.6.3, p. 43.

Crossrefs

Cf. A002117 (zeta(3)), A197070 (3*zeta(3)/4), A233091 (7*zeta(3)/8), A076788 (alternating sum with denominator n), A152648 (non-alternating sum with denominator n^2), A152649 (non-alternating sum with denominator n^3), A233033 (alternating sum with denominator n^3).

Programs

  • Mathematica
    RealDigits[ 5*Zeta[3]/8, 10, 100] // First

Formula

Equals 5*zeta(3)/8.
Equals -Integral_{x=0..1} (log(1+x)*log(1-x)/x)*dx. - Amiram Eldar, May 06 2023
Equals Sum_{m>=1} Sum_{n>=1} (-1)^(m-1)/(m*n*(m + n)) (see Finch). - Stefano Spezia, Nov 02 2024

A099218 Decimal expansion of Li_4(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

References

  • Alexander Apelblat, Tables of Integrals and Series, Harri Deutsch, (1996), Section 1.3.2.

Crossrefs

Programs

Formula

Li_4(1/2)=sum(k>0, 1/2^k/k^4)=0.5174790616738993863...

Extensions

Leading zero removed, formula value corrected by R. J. Mathar, Feb 05 2009

A099217 Decimal expansion of Li_3(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

Examples

			0.537213193608040200940623225594965826670402499340...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.6.3, p. 44.
  • L. Lewin, Polylogarithms and associated Functions, North Holland (1981) A.2.6(3)

Crossrefs

Programs

Formula

Li_3(1/2) = Sum_{k>0} 1/(2^k*k^3) = 0.537213193608...
Li_3(1/2) = 7*zeta(3)/8-Pi^2*log(2)/12+log(2)^3/6. - Benoit Cloitre, May 22 2006

Extensions

Leading zero removed by R. J. Mathar, Feb 05 2009

A099219 Decimal expansion of Li_5(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

Examples

			0.50840057924...
		

References

  • Alexander Apelblat, Tables of Integrals and Series, Harri Deutsch (1996), Section 1.3.2.

Crossrefs

Programs

Formula

Li_5(1/2) = Sum_{k>0} 1/2^k/k^5.

A099220 Decimal expansion of Li_6(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

Crossrefs

Programs

Formula

Li_6(1/2)=sum(k>0, 1/2^k/k^6)=0.5040953978...

A099221 Decimal expansion of Li_7(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

Crossrefs

Programs

Formula

Li_7(1/2)=sum(k>0, 1/2^k/k^7)=0.50201456332470849456....

Extensions

Formula value corrected and leading zero removed by R. J. Mathar, Feb 05 2009

A099222 Decimal expansion of Li_8(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

Crossrefs

Programs

Formula

Li_8(1/2)=sum(k>0, 1/2^k/k^8)=0.500996659...

A099223 Decimal expansion of Li_9(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

Crossrefs

Programs

Formula

Li_9(1/2)=sum(k>0, 1/2^k/k^9)=0.5004948881...

A099224 Decimal expansion of Li_{10}(1/2).

Original entry on oeis.org

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

Views

Author

Benoit Cloitre, Oct 06 2004

Keywords

Crossrefs

Programs

Formula

Li_{10}(1/2)=sum(k>0, 1/2^k/k^10)=0.500246320606006775...

A274181 Decimal expansion of Phi(1/2, 2, 2), where Phi is the Lerch transcendent.

Original entry on oeis.org

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

Views

Author

Johannes W. Meijer and N. H. G. Baken, Jun 17 2016, Jul 08 2016

Keywords

Comments

The exponential integral distribution is defined by p(x, m, n, mu) = ((n+mu-1)^m * x^(mu-1) / (mu-1)!) * E(x, m, n), see A163931 and the Meijer link. The moment generating function of this probability distribution function is M(a, m, n, mu) = Sum_{k>=0}(((mu+k-1)!/((mu-1)!*k!)) * ((n+mu-1) / (n+mu+k-1))^m * a^k).
In the special case that mu=1 we get p(x, m, n, mu=1) = n^m * E(x, m, n) and M(a, m, n, mu=1) = n^m * Phi(a, m, n), with Phi the Lerch transcendent. If n=1 and mu=1 we get M(a, m, n=1, mu=1) = polylog(m, a)/a = Li_m(a)/a.

Examples

			0.32896210586005002361062528063872043497679389922...
		

References

  • William Feller, An introduction to probability theory and its applications, Vol. 1. p. 285, 1968.

Crossrefs

Cf. A163931, A002162 (Phi(1/2, 1, 1)/2), A076788 (Phi(1/2, 2, 1)/2), A112302, A008276.

Programs

  • Maple
    Digits := 101; c := evalf(LerchPhi(1/2, 2, 2));
  • Mathematica
    N[HurwitzLerchPhi[1/2, 2, 2], 25] (* G. C. Greubel, Jun 19 2016 *)
  • PARI
    Pi^2/3 - 2*log(2)^2 - 2 \\ Altug Alkan, Jul 08 2016
    
  • PARI
    lerchphi(.5,2,2) \\ Charles R Greathouse IV, Jan 30 2025
    
  • Python
    from mpmath import mp, lerchphi
    mp.dps=102
    print([int(d) for d in list(str(lerchphi(1/2, 2, 2))[2:-1])]) # Indranil Ghosh, Jul 04 2017

Formula

Equals Phi(1/2, 2, 2) with Phi the Lerch transcendent.
Equals Sum_{k>=0}(1/((2+k)^2*2^k)).
Equals 4 * polylog(2, 1/2) - 2.
Equals Pi^2/3 - 2*log(2)^2 - 2.
Equals Integral_{x=0..oo} x*exp(-x)/(exp(x)-1/2) dx. - Amiram Eldar, Aug 24 2020
Showing 1-10 of 27 results. Next