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 1-6 of 6 results.

A259148 Decimal expansion of phi(exp(-Pi)), where phi(q) = Product_{n>=1} (1-q^n) is the Euler modular function.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 19 2015

Keywords

Examples

			0.954918789987674103751233978110291077632715373807805283148799191676094...
		

Crossrefs

Cf. A048651 phi(1/2), A100220 phi(1/3), A100221 phi(1/4), A100222 phi(1/5), A132034 phi(1/6), A132035 phi(1/7), A132036 phi(1/8), A132037 phi(1/9), A132038 phi(1/10), A368211 phi(exp(-Pi/16)), A292862 phi(exp(-Pi/8)), A292863 phi(exp(-Pi/4)), A259147 phi(exp(-Pi/2)), A259149 phi(exp(-2*Pi)), A292888 phi(exp(-3*Pi)), A259150 phi(exp(-4*Pi)), A292905 phi(exp(-5*Pi)), A363018 phi(exp(-6*Pi)), A363117 phi(exp(-7*Pi)), A259151 phi(exp(-8*Pi)), A363118 phi(exp(-9*Pi)), A363019 phi(exp(-10*Pi)), A363081 phi(exp(-11*Pi)), A363020 phi(exp(-12*Pi)), A363178 phi(exp(-13*Pi)), A363119 phi(exp(-14*Pi)), A363179 phi(exp(-15*Pi)), A292864 phi(exp(-16*Pi)), A363120 phi(exp(-18*Pi)), A363021 phi(exp(-20*Pi)).

Programs

  • Mathematica
    phi[q_] := QPochhammer[q, q]; RealDigits[phi[Exp[-Pi]], 10, 104] // First

Formula

phi(q) = QPochhammer(q,q) = (q;q)_infinity.
phi(q) also equals theta'(1, 0, sqrt(q))^(1/3)/(2^(1/3)*q^(1/24)), where theta' is the derivative of the elliptic theta function theta(a,u,q) w.r.t. u.
phi(exp(-Pi)) = exp(Pi/24)*Gamma(1/4)/(2^(7/8)*Pi^(3/4)).
Equals 1/exp(A255695). - Hugo Pfoertner, May 28 2025

A292820 Decimal expansion of Product_{k>=1} (1 + exp(-Pi*k)).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Sep 24 2017

Keywords

Examples

			1.045250214354711942547595012203562068003424782155586915500520985257117...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[E^(Pi/24) / 2^(1/8), 10, 120][[1]]
    RealDigits[QPochhammer[-1, E^(-Pi)]/2, 10, 120][[1]]
  • PARI
    exp(Pi/24)/sqrtn(2,8) \\ Charles R Greathouse IV, Mar 13 2018

Formula

Equals exp(Pi/24) / 2^(1/8).
Equals A259149 / A259148.

A292824 Decimal expansion of Product_{k>=1} (1 - exp(-Pi*(2*k-1))).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Sep 24 2017

Keywords

Examples

			0.956708725113587003449038717361890724715615702454393013400916466527611...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[2^(1/8) * E^(-Pi/24), 10, 120][[1]]

Formula

Equals 2^(1/8) * exp(-Pi/24).
Equals A259148 / A259149.

A292827 Decimal expansion of Product_{k>=1} (1 + exp(-Pi*(2*k-1)/2)).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Sep 24 2017

Keywords

Examples

			1.219224801998773577179427484349023235631844499700916838279952481630782...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[2^(1/16) / (E^(Pi/48) * (Sqrt[2]-1)^(1/4)), 10, 120][[1]]

Formula

Equals 2^(1/16) / (exp(Pi/48) * (sqrt(2)-1)^(1/4)).
Equals A292819 / A292820.

A292829 Decimal expansion of Product_{k>=1} (1 + exp(-2*Pi*(2*k-1))).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Sep 24 2017

Keywords

Examples

			1.001867449256304435105432750510732150159885395483789405664498761179818...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[2^(1/16) / (E^(Pi/12) * (Sqrt[2]-1)^(1/4)), 10, 120][[1]]

Formula

Equals 2^(1/16) / (exp(Pi/12) * (sqrt(2)-1)^(1/4)).
Equals A292821 / A292822.

A354296 Decimal expansion of Product_{k>=1} (1 - exp(-2*k*Pi/sqrt(3))).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, May 23 2022

Keywords

Comments

Note that Prudnikov incorrectly give this product as 3^(1/4)*exp(-Pi*sqrt(3)/18), which differs from the correct result by 0.0000182...

Examples

			0.972713586936242371513055024334538082849547588619101318683993472802594...
		

References

  • A. P. Prudnikov, Yu. A. Brychkov, and O. I. Marichev, Integrals and Series, Vol. 1 (Overseas Publishers Association, Amsterdam, 1986), p. 757, section 6.2.3, incorrect formula 4.

Crossrefs

Cf. A292828.

Programs

  • Maple
    evalf(Product(1 - exp(-2*k*Pi/sqrt(3)), k = 1..infinity), 105);
  • Mathematica
    RealDigits[QPochhammer[E^(-2*Pi/Sqrt[3])], 10, 105][[1]]
  • PARI
    prodinf(k=1, (1 - exp(-2*k*Pi/sqrt(3))))
Showing 1-6 of 6 results.