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 1-7 of 7 results.

A013662 Decimal expansion of zeta(4).

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			1.082323233711138191516003696541167...
		

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 811.
  • Louis Comtet, Advanced Combinatorics, Reidel, 1974, p. 89, Exercise.
  • John H. Conway and Richard K. Guy, The Book of Numbers, New York: Springer-Verlag, 1996. See p. 262.
  • Richard K. Guy, Unsolved Problems in Number Theory, 3rd Edition, Springer, 2004, Section F17, Series associated with the zeta-function, p. 391.
  • L. D. Landau and E. M. Lifschitz, Band V, Statistische Physik, Akademie Verlag, 1966, pp. 172 and 180-181.
  • Paulo Ribenboim, The Little Book of Bigger Primes, Springer-Verlag NY 2004. See p. 162.
  • David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987, p. 33.

Crossrefs

Programs

  • Magma
    SetDefaultRealField(RealField(110)); L:=RiemannZeta(); Evaluate(L,4); // G. C. Greubel, May 30 2019
    
  • Maple
    evalf(Pi^4/90,120); # Muniru A Asiru, Sep 19 2018
  • Mathematica
    RealDigits[Zeta[4],10,120][[1]] (* Harvey P. Dale, Dec 18 2012 *)
  • Maxima
    ev(zeta(4),numer) ; /* R. J. Mathar, Feb 27 2012 */
    
  • PARI
    default(realprecision, 20080); x=Pi^4/90; for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b013662.txt", n, " ", d)); \\ Harry J. Smith, Apr 29 2009
    
  • Sage
    numerical_approx(zeta(4), digits=100) # G. C. Greubel, May 30 2019

Formula

zeta(4) = Pi^4/90 = A092425/90. - Harry J. Smith, Apr 29 2009
From Peter Bala, Dec 03 2013: (Start)
Definition: zeta(4) := Sum_{n >= 1} 1/n^4.
zeta(4) = (4/17)*Sum_{n >= 1} ( (1 + 1/2 + ... + 1/n)/n )^2 and
zeta(4) = (16/45)*Sum_{n >= 1} ( (1 + 1/3 + ... + 1/(2*n-1))/n )^2 (see Borwein and Borwein).
zeta(4) = (256/90)*Sum_{n >= 1} n^2*(4*n^2 + 3)*(12*n^2 + 1)/(4*n^2 - 1)^5.
Series acceleration formulas:
zeta(4) = (36/17)*Sum_{n >= 1} 1/( n^4*binomial(2*n,n) ) (Comtet)
= (36/17)*Sum_{n >= 1} P(n)/( (2*n*(2*n - 1))^4*binomial(4*n,2*n) )
= (36/17)*Sum_{n >= 1} Q(n)/( (3*n*(3*n - 1)*(3*n - 2))^4*binomial(6*n,3*n) ),
where P(n) = 80*n^4 - 48*n^3 + 24*n^2 - 8*n + 1 and Q(n) = 137781*n^8 - 275562*n^7 + 240570*n^6 - 122472*n^5 + 41877*n^4 - 10908*n^3 + 2232*n^2 - 288*n + 16 (see section 8 in the Bala link). (End)
zeta(4) = 2/3*2^4/(2^4 - 1)*( Sum_{n even} n^2*p(n)/(n^2 - 1)^5 ), where p(n) = 3*n^4 + 10*n^2 + 3 is a row polynomial of A091043. See A013664, A013666, A013668 and A013670. - Peter Bala, Dec 05 2013
zeta(4) = Sum_{n >= 1} ((floor(sqrt(n))-floor(sqrt(n-1)))/n^2). - Mikael Aaltonen, Jan 18 2015
zeta(4) = Product_{k>=1} 1/(1 - 1/prime(k)^4). - Vaclav Kotesovec, May 02 2020
From Wolfdieter Lang, Sep 16 2020: (Start)
zeta(4) = (1/3!)*Integral_{x=0..oo} x^3/(exp(x) - 1) dx. See Abramowitz-Stegun, 23.2.7., for s=2, p. 807, and Landau-Lifschitz, Band V, p. 172, eq. (4), for x=4. See also A231535.
zeta(4) = (4/21)*Integral_{x=0..oo} x^3/(exp(x) + 1) dx. See Abramowitz-Stegun, 23.2.8., for s=2, p. 807, and Landau-Lifschitz, Band V, p. 172, eq. (1), for x=4. See also A337711. (End)
zeta(4) = (72/17) * Integral_{x=0..Pi/3} x*(log(2*sin(x/2)))^2. See Richard K. Guy reference. - Bernard Schott, Jul 20 2022
From Peter Bala, Nov 12 2023: (Start)
zeta(4) = 1 + (4/3)*Sum_{k >= 1} (1 - 2*(-1)^k)/(k*(k + 1)^4*(k + 2)) = 35053/32400 + 48*Sum_{k >= 1} (1 - 2*(-1)^k)/(k*(k + 1)*(k + 2)*(k + 3)^4*(k + 4)*(k + 5)*(k + 6)).
More generally, it appears that for n >= 0, zeta(4) = c(n) + (4/3)*(2*n + 1)!^2 * Sum_{k >= 1} (1 - 2*(-1)^k)/( (k + 2*n + 1)^3*Product_{i = 0..4*n+2} (k + i) ), where {c(n) : n >= 0} is a sequence of rational approximations to zeta(4) beginning [1, 35053/32400, 2061943067/ 1905120000, 18594731931460103/ 17180389306080000, 257946156103293544441/ 238326360453941760000, ...]. (End)
From Peter Bala, Apr 27 2025: (Start)
zeta(4) = 1/4! * Integral_{x >= 0} x^4 * exp(x)/(exp(x) - 1)^2 dx = 8/7 * 1/4! * Integral_{x >= 0} x^4 * exp(x)/(exp(x) + 1)^2 dx.
zeta(4) = 1/5! * Integral_{x >= 0} x^5 * exp(x)*(exp(x) + 1)/(exp(x) - 1)^3 dx = 1/(3*5*7) * Integral_{x >= 0} x^5 * exp(x)*(exp(x) - 1)/(exp(x) + 1)^3 dx. (End)
10*zeta(4) = Sum_{k>=1} H(k)^3/(k*(k+1)), where H(k) = A001008(k)/A002805(k) is the k-th harmonic number (Ramachandra, 1981). - Amiram Eldar, May 30 2025
zeta(4) = Integral_{x=0..1} Li(3,x)/x dx, where Li(n,x) is the polylogarithm function. - Kritsada Moomuang, Jun 14 2025
zeta(4) = Sum_{i, j >= 1} 1/(i^3*j*binomial(i+j, i)) = 4/3 * Sum_{i, j >= 1} 1/(i^2*j^2*binomial(i+j, i)). - Peter Bala, Aug 03 2025

A340065 Decimal expansion of the Product_{p>=2} 1+p^2/((p-1)^2*(p+1)^2) where p are successive prime numbers A000040.

Original entry on oeis.org

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

Views

Author

Artur Jasinski, Dec 28 2020

Keywords

Comments

This is a rational number.
This constant does not belong to the infinite series of prime number products of the form: Product_{p>=2} (p^(2*n)-1)/(p^(2*n)+1),
which are rational numbers equal to zeta(4*n)/(zeta(2*n))^2 = A114362(n+1)/A114363(n+1).
This number has decimal period length 230:
1.81(0781476121562952243125904486251808972503617945007235890014471780028943
5600578871201157742402315484804630969609261939218523878437047756874095
5137481910274963820549927641099855282199710564399421128798842257597684
51519536903039073806).

Examples

			1.8107814761215629522431259...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[5005/2764,105]][[1]]
  • PARI
    default(realprecision,105)
    prodeulerrat(1+p^2/((p-1)^2*(p+1)^2))

Formula

Equals 5005/2764 = 5*7*11*13/(2^2*691).
Equals Product_{n>=1} 1+A000040(n)^2/A084920(n)^2.
Equals (13/9)*A340066.
From Vaclav Kotesovec, Dec 29 2020: (Start)
Equals 3/2 * (Product_{p prime} (p^6+1)/(p^6-1)) * (Product_{p prime} (p^4+1)/(p^4-1)).
Equals 7*zeta(6)^2 / (4*zeta(12)).
Equals -7*binomial(12, 6) * Bernoulli(6)^2 / (8*Bernoulli(12)). (End)
Equals Sum_{k>=1} A005361(k)/k^2. - Amiram Eldar, Jan 23 2024

A257134 Decimal expansion of Pi^4/45.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Apr 16 2015

Keywords

Examples

			2.16464646742227638303200739308233580554950190383745381536595243...
		

References

  • L. J. P. Kilford, Modular Forms: A Classical and Computational Introduction, Imperial College Press, 2008, p. 15.

Crossrefs

Programs

Formula

Pi^4/45 = 2*zeta(4) = G_4(oo), where the function G_k(z) is the Eisenstein nonzero modular form of weight k.
Equals -Integral_{x=0..1} log(x)^2 * log(1 - x)/x dx. - Amiram Eldar, Jul 21 2020
Equals Sum_{n,m>=1} (Pi^2/6 - Sum_{k=1..n+m} 1/k^2)/(n*m) (Tissier, 1999). - Amiram Eldar, Jan 27 2024
Equals Integral_{x=0..1} Li(3,sqrt(x))/x dx, where Li(n,x) is the polylogarithm function. - Kritsada Moomuang, Jun 18 2025
Equals 2*A013662 = A231535/3. - Hugo Pfoertner, Jun 18 2025

A337710 Decimal expansion of 8*Pi^6/63 = 5!*zeta(6).

Original entry on oeis.org

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

Views

Author

Wolfdieter Lang, Sep 16 2020

Keywords

Examples

			122.081167438133896765742151574910463348218098803...
		

Crossrefs

Cf. A013664, A231535 (Integral with x^3).

Programs

Formula

Equals Integral_{x>=0} x^5/(exp(x) - 1) dx = 5!*A013664.
Equals -Integral_{x=0..1} log(x)^5/(1-x) dx. - Amiram Eldar, May 27 2021

A337711 Decimal expansion of (7/120)*Pi^4 = (21/4)*zeta(4).

Original entry on oeis.org

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

Views

Author

Wolfdieter Lang, Sep 16 2020

Keywords

Comments

Equals Integral_{0..infinity} x^3/(exp(x) + 1) dx = (7/120)*Pi^4 = (21/4)*A013662. (Fermi-Dirac). See Abramowitz-Stegun, 23.2.8, for s=4, p. 807, and Landau-Lifschitz, eq. (1), for x=4, p. 172.

Examples

			5.68219697698347550545901940684113148956744249757331626533562...
		

References

  • L. D. Landau and E. M. Lifschitz, Band V, Statistische Physik, Akademie Verlag, 1966, eq. (1) for x=4, p. 172.

Crossrefs

Cf. A013662, A231535 (Planck, Bose-Einstein integral).

Programs

  • Mathematica
    RealDigits[7*Pi^4/120, 10, 100][[1]] (* Amiram Eldar, May 27 2021 *)

Formula

Equals -Integral_{x=0..1} log(x)^3/(x+1) dx. - Amiram Eldar, May 27 2021

A340066 Decimal expansion of the Product_{p>=3} 1+p^2/((p-1)^2*(p+1)^2) where p are successive prime numbers A000040.

Original entry on oeis.org

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

Views

Author

Artur Jasinski, Dec 28 2020

Keywords

Comments

This is a rational number.
This constant does not belong to the infinite series of prime number products of the form: Product_{p>=2} (p^(2*n)-1)/(p^(2*n)+1),
which are rational numbers equal to zeta(4*n)/zeta^2(2*n) = A114362(n+1)/A114363(n+1).
This number has decimal period length 230:
1.25(3617945007235890014471780028943560057887120115774240231548480463096960
9261939218523878437047756874095513748191027496382054992764109985528219
9710564399421128798842257597684515195369030390738060781476121562952243
12590448625180897250).

Examples

			1.25361794500723589001447178...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[3465/2764, 105]][[1]]
  • PARI
    default(realprecision, 105)
    prodeulerrat(1+p^2/((p-1)^2*(p+1)^2),1,3)

Formula

Equals 3465/2764 = 3^2*5*7*11/(2^2*691).
Equals Product_{n>=2} 1+A000040(n)^2/A084920(n)^2.
Equals (9/13)*A340065.

A365251 Decimal expansion of the absolute value of psi^(4)(1), the fourth derivative of the digamma function at 1.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Aug 29 2023

Keywords

Examples

			psi^(4)(1) = -24.88626612344087823195277167496882...
		

Crossrefs

Cf. A013663, A231535 (3rd deriv), A152648 (2nd deriv), A013661 (1st deriv).

Programs

  • Maple
    evalf(Psi(4,1)) ;
  • Mathematica
    RealDigits[24*Zeta[5], 10, 100][[1]] (* Amiram Eldar, Aug 29 2023 *)
  • PARI
    psi''''(1) \\ Michel Marcus, Aug 29 2023

Formula

Equals 24*A013663.
Showing 1-7 of 7 results.