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 14 results. Next

A109219 Decimal expansion of Product_{n >= 2} 1-n^(-3).

Original entry on oeis.org

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

Views

Author

Zak Seidov, Apr 17 2006

Keywords

Comments

The physical applications of this kind of product (with s<0) can be found in the Klauder et al. reference. - Karol A. Penson, Feb 24 2006

Examples

			0.809396597366290109578680478726382119372787648261130...
		

Crossrefs

Programs

Formula

Equals cosh((sqrt(3)*Pi)/2)/(3*Pi).
Product_{n >= 2} (1 - 1/n^p) simplifies, if p is odd, to 1/(p * Product_{j=1..p-1} Gamma(-(-1)^(j*(1 + 1/p)))) and, if p is even, to the elementary (Product_{j=1..p/2-1} sin(Pi*(-1)^(2*j/p))/(Pi*i)) / p. - David W. Cantrell, Feb 24 2006
Equals exp(Sum_{j>=1} (1 - zeta(3*j))/j). - Vaclav Kotesovec, Apr 27 2020
Equals 1/(Gamma((5-i*sqrt(3))/2)*Gamma((5+i*sqrt(3))/2)). - Amiram Eldar, Sep 01 2020

Extensions

Corrected and extended by T. D. Noe, Apr 24 2006

A073017 Decimal expansion of the Product_{n>=1} (1 + 1/n^3).

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Aug 03 2002

Keywords

Comments

Let X_1, X_2, ... be a sequence of independent Bernoulli trials with probability of success 1/n^3. Let Y be the position of the last success in the sequence. 1.428189... is the expected value of Y. - Geoffrey Critzer, Aug 19 2019
If m tends to infinity, Product_{k>=1} (1 + m/k^3) ~ exp(2*Pi*m^(1/3)/sqrt(3)) / (2^(3/2)*Pi^(3/2)*sqrt(m)). - Vaclav Kotesovec, Aug 30 2024

Examples

			2.42818979209887032873604143617914635811836294478339049763...
		

Crossrefs

Programs

Formula

Equals cosh(1/2 * sqrt(3) * Pi)/Pi.
Equals exp(Sum_{j>=1} (-(-1)^j*zeta(3*j)/j)). - Vaclav Kotesovec, Mar 28 2019
Equals Product_{n>=1} (1 + 1/(n^2 + n)). - Amiram Eldar, Sep 01 2020
Equals 3*Product_{n >= 2} (1-n^(-3)) = 3*A109219. - Robert FERREOL, Oct 06 2021

A175617 Decimal expansion of product_{n>=2} (1-n^(-6)).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jul 26 2010

Keywords

Examples

			0.9826842777...
		

Crossrefs

Programs

  • Maple
    cosh(Pi*sqrt(3)/2)^2/6/Pi^2 ; evalf(%) ;
  • Mathematica
    RealDigits[(1 + Cosh[Sqrt[3]*Pi])/(12*Pi^2), 10, 105] // First (* Jean-François Alcover, Feb 12 2013 *)
  • PARI
    exp(suminf(j=1, (1 - zeta(6*j))/j)) \\ Vaclav Kotesovec, Apr 27 2020

Formula

Equals product_{t=1..5} 1/Gamma(2-exp(Pi*i*t/3)), where i is the imaginary unit and Pi/3 = A019670.
Equals exp(Sum_{j>=1} (1 - zeta(6*j))/j). - Vaclav Kotesovec, Apr 27 2020

A258870 Decimal expansion of Product_{n>=1} (1+1/n^4).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Jun 13 2015

Keywords

Comments

For m>0, Product_{k>=1} (1 + m/k^4) = (cosh(sqrt(2)*Pi*m^(1/4)) - cos(sqrt(2)*Pi*m^(1/4))) / (2*Pi^2*sqrt(m)). - Vaclav Kotesovec, Aug 30 2024

Examples

			2.16736062588226195190023136684702744182161317296349850975623259988...
		

Crossrefs

Programs

  • Maple
    evalf((cosh(sqrt(2)*Pi)-cos(sqrt(2)*Pi))/(2*Pi^2),120);
  • Mathematica
    RealDigits[(Cosh[Sqrt[2]*Pi]-Cos[Sqrt[2]*Pi])/(2*Pi^2),10,120][[1]]
  • PARI
    exp(sumalt(j=1, -(-1)^j*zeta(4*j)/j)) \\ Vaclav Kotesovec, Dec 15 2020

Formula

Equals (cosh(sqrt(2)*Pi)-cos(sqrt(2)*Pi))/(2*Pi^2).
Equals exp(Sum_{j>=1} (-(-1)^j*Zeta(4*j)/j)). - Vaclav Kotesovec, Mar 28 2019

A175619 Decimal expansion of Product_{n>=2} (1-n^(-8)).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jul 26 2010

Keywords

Examples

			0.9959233150... = (255/256)*(6560/6561)*(65535/65536)*...
		

Crossrefs

Programs

  • Maple
    t := Pi/sqrt(2) ; sinh(Pi)*((sin(t)*cosh(t))^2+(cos(t)*sinh(t))^2)/8/Pi^3 ; evalf(%) ;
  • Mathematica
    RealDigits[ -Sin[(-1)^(1/4)*Pi]*Sin[(-1)^(3/4)*Pi]*Sinh[Pi] / (8*Pi^3) // Re, 10, 105] // First(* Jean-François Alcover, Feb 12 2013 *)
  • PARI
    exp(suminf(j=1, (1 - zeta(8*j))/j)) \\ Vaclav Kotesovec, Apr 27 2020
    
  • PARI
    prodnumrat(1-x^-8, 2) \\ Charles R Greathouse IV, Feb 04 2025

Formula

Equals (cosh(sqrt(2)*Pi) - cos(sqrt(2)*Pi)) * sinh(Pi) / (16*Pi^3). - Vaclav Kotesovec, Apr 27 2020
Equals exp(Sum_{j>=1} (1 - zeta(8*j))/j). - Vaclav Kotesovec, Apr 27 2020

A258871 Decimal expansion of Product_{n>=1} (1+1/n^6).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Jun 13 2015

Keywords

Comments

From Vaclav Kotesovec, Aug 30 2024: (Start)
For m>0, Product_{k>=1} (1 + m/k^6) = (cosh(Pi*m^(1/6)) - cos(sqrt(3)*Pi*m^(1/6))) * sinh(Pi*m^(1/6)) / (2*Pi^3*sqrt(m)).
If m tends to infinity, Product_{k>=1} (1 + m/k^6) ~ exp(2*Pi*m^(1/6)) / (8*Pi^3*sqrt(m)). (End)

Examples

			2.03474083500942906358682080964285089771090100623925469055753948...
		

Crossrefs

Programs

  • Maple
    evalf((cosh(Pi)-cos(sqrt(3)*Pi))*sinh(Pi)/(2*Pi^3), 120);
  • Mathematica
    RealDigits[(Cosh[Pi]-Cos[Sqrt[3]*Pi])*Sinh[Pi]/(2*Pi^3),10,120][[1]]
  • PARI
    prodnumrat(1+x^-6, 1) \\ Charles R Greathouse IV, Feb 04 2025

Formula

Equals (cosh(Pi)-cos(sqrt(3)*Pi))*sinh(Pi)/(2*Pi^3).
Equals exp(Sum_{j>=1} (-(-1)^j*Zeta(6*j)/j)). - Vaclav Kotesovec, Mar 28 2019

A334411 Decimal expansion of Product_{k>=1} (1 + 1/k^8).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Apr 27 2020

Keywords

Comments

From Vaclav Kotesovec, Aug 30 2024: (Start)
For m>0, Product_{k>=1} (1 + m/k^8) = (cosh(Pi*sqrt(2 - sqrt(2))*m^(1/8)) - cos(Pi*sqrt(2 + sqrt(2))*m^(1/8))) * (cosh(Pi*sqrt(2 + sqrt(2))*m^(1/8)) - cos(Pi*sqrt(2 - sqrt(2))*m^(1/8)))/(4*sqrt(m)*Pi^4).
If m tends to infinity, Product_{k>=1} (1 + m/k^8) ~ exp(Pi*sqrt(2*(2 + sqrt(2)))*m^(1/8)) / (16*Pi^4*sqrt(m)).
In general, if m tends to infinity and v > 2, Product_{k>=1} (1 + m/k^v) ~ exp(Pi*m^(1/v)/sin(Pi/v)) / ((2*Pi)^(v/2)*sqrt(m)). (End)

Examples

			2.00815605499274531514903948232341369211953215983095097877074299617422...
		

Crossrefs

Programs

  • Maple
    evalf(Product(1 + 1/j^8, j = 1..infinity), 120);
  • Mathematica
    RealDigits[Chop[N[Product[(1 + 1/n^8), {n, 1, Infinity}], 120]]][[1]]
  • PARI
    default(realprecision, 120); exp(sumalt(j=1, -(-1)^j*zeta(8*j)/j))

Formula

Equals exp(Sum_{j>=1} (-(-1)^j*Zeta(8*j)/j)).
Equals (cos(sqrt(4 - 2*sqrt(2))*Pi) + cos(sqrt(4 + 2*sqrt(2))*Pi) + cosh(sqrt(4 - 2*sqrt(2))*Pi) + cosh(sqrt(4 + 2*sqrt(2))*Pi) - 2*cos(sqrt(2 - sqrt(2))*Pi) * cosh(sqrt(2 - sqrt(2))*Pi) - 2*cos(sqrt(2 + sqrt(2))*Pi) * cosh(sqrt(2 + sqrt(2))*Pi)) / (8*Pi^4).

A175616 Decimal expansion of product_{n>=2} (1-n^(-5)).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jul 26 2010

Keywords

Examples

			0.96325656175755909737304603488397519554352075785342263739516...
		

Crossrefs

Programs

  • Mathematica
    g[k_] := Gamma[Root[1 - # + #^2 - #^3 + #^4 & , k]]; RealDigits[ 1/(5*g[1]*g[2]*g[3]*g[4]) // Re, 10, 105] // First (* Jean-François Alcover, Feb 12 2013 *)
  • PARI
    exp(suminf(j=1, (1 - zeta(5*j))/j)) \\ Vaclav Kotesovec, Apr 27 2020

Formula

Equals product_{t=1..4} 1/Gamma(2-exp(2*Pi*i*t/5)), where i is the imaginary unit.
Equals exp(Sum_{j>=1} (1 - zeta(5*j))/j). - Vaclav Kotesovec, Apr 27 2020
Equals 1/(Gamma(2 + phi/2 - i*(5^(1/4) / (2*sqrt(phi)))) * Gamma(2 + phi/2 + i*(5^(1/4) / (2*sqrt(phi)))) * Gamma(2 - 1/(2*phi) - i*5^(1/4)*(sqrt(phi)/2)) * Gamma(2 - 1/(2*phi) + i*5^(1/4)*(sqrt(phi)/2))), where phi = A001622 = (1+sqrt(5))/2 is the golden ratio and i is the imaginary unit. - Vaclav Kotesovec, Dec 15 2020

A175618 Decimal expansion of product_{n>=2} (1-n^(-7)).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jul 26 2010

Keywords

Examples

			0.99165495...
		

Crossrefs

Programs

  • Mathematica
    N[1/(7*Product[ Gamma[(-1)^(8*k/7 + 1)], {k, 1, 6}]), 105] // Re // RealDigits // First (* Jean-François Alcover, Feb 05 2013 *)
  • PARI
    exp(suminf(j=1, (1 - zeta(7*j))/j)) \\ Vaclav Kotesovec, Dec 15 2020

Formula

Equals 1/product_{t=1..6} Gamma(2-exp(2*Pi*i*t/7)), where i is the imaginary unit and 2*Pi/7 = A019695.
Equals exp(Sum_{j>=1} (1 - zeta(7*j))/j). - Vaclav Kotesovec, Dec 15 2020

A330864 Decimal expansion of sinh(Pi/2)/2.

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Apr 28 2020

Keywords

Comments

This constant is transcendental.

Examples

			(1 + 1/2^2) * (1 - 1/3^2) * (1 + 1/4^2) * (1 - 1/5^2) * (1 + 1/6^2) * ... = (e^(Pi/2) - e^(-Pi/2))/4 = 1.15064945115364743673152001...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sinh[Pi/2]/2, 10, 110] [[1]]
  • PARI
    sinh(Pi/2)/2 \\ Michel Marcus, Apr 28 2020

Formula

Equals Sum_{k>=1} Pi^(2*k-1)/(4^k*(2*k-1)!).
Equals Product_{k>=2} (1 + (-1)^k/k^2).
Equals (i^(-i) - i^i)/4, where i is the imaginary unit.
Showing 1-10 of 14 results. Next