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.

A010774 Decimal expansion of 12th root of 2.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

This number figures in our standard 12-tone tuning of music today.
It represents the frequency ratio of a semitone in equal temperament. The equal-tempered chromatic scale divides the octave, which has a ratio of 2:1, into twelve parts of equal ratio: [2^(n/12), 2^((n+1)/12)), 0 <= n <= 11. - Daniel Forgues, Feb 28 2013

Examples

			2^(1/12) = 1.059463094359295264561825294946341700779204317494...
		

References

  • D. Coulter, Digital Audio Processing. Berkeley, California: Focal Press (2000) p. 30
  • Ian Stewart, Professor Stewart's Incredible Numbers, London, Profile Books, 2015, pp. 217-228.

Crossrefs

Programs

Formula

Equals Product_{k>=0} (1 + (-1)^k/(12*k + 11)). - Amiram Eldar, Jul 29 2020
Equals sqrt(A010768). - Hugo Pfoertner, May 31 2024

A203145 Decimal expansion of Gamma(5/6).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Dec 29 2011

Keywords

Examples

			1.1287870299081259612609010902588420133267874416647554517520...
		

Crossrefs

Programs

Formula

A073005 * this * A231863 * A010768 = A073006. - R. J. Mathar, Jan 15 2021
Equals 2*Pi/Gamma(1/6) = A019692 / A175379. - Amiram Eldar, Jul 04 2023
Equals 2^(4/3) * Pi^(3/2) / (sqrt(3) * Gamma(1/3)^2). - Vaclav Kotesovec, Jul 04 2023

A329219 Decimal expansion of 2^(10/12) = 2^(5/6).

Original entry on oeis.org

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

Views

Author

Jianing Song, Nov 08 2019

Keywords

Comments

2^(10/12) is the ratio of the frequencies of the pitches in a minor seventh (e.g., D4-C5) in 12-tone equal temperament.

Examples

			1.78179743...
		

Crossrefs

Frequency ratios of musical intervals:
Perfect unison: 2^(0/12) = 1.0000000000
Minor second: 2^(1/12) = 1.0594630943... (A010774)
Major second: 2^(2/12) = 1.1224620483... (A010768)
Minor third: 2^(3/12) = 1.1892071150... (A010767)
Major third: 2^(4/12) = 1.2599210498... (A002580)
Perfect fourth: 2^(5/12) = 1.3348398541... (A329216)
Aug. fourth/
Dim. fifth: 2^(6/12) = 1.4142135623... (A002193)
Perfect fifth: 2^(7/12) = 1.4983070768... (A328229)
Minor sixth: 2^(8/12) = 1.5874010519... (A005480)
Major sixth: 2^(9/12) = 1.6817928305... (A011006)
Minor seventh: 2^(10/12) = 1.7817974362... (this sequence)
Major seventh: 2^(11/12) = 1.8877486253... (A329220)
Perfect octave: 2^(12/12) = 2.0000000000

Programs

  • Mathematica
    First[RealDigits[2^(5/6), 10, 100]] (* Paolo Xausa, Apr 27 2024 *)
  • PARI
    default(realprecision, 100); 2^(10/12)

Formula

Equals 2/A010768.
Equals Product_{k>=0} (1 + (-1)^k/(6*k + 1)). - Amiram Eldar, Jul 25 2020

A329216 Decimal expansion of 2^(5/12).

Original entry on oeis.org

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

Views

Author

Jianing Song, Nov 08 2019

Keywords

Comments

2^(5/12) is the ratio of the frequencies of the pitches in a perfect fourth (e.g., D4-G4) in 12-tone equal temperament.

Crossrefs

Frequency ratios of musical intervals:
Perfect unison: 2^(0/12) = 1.0000000000
Minor second: 2^(1/12) = 1.0594630943... (A010774)
Major second: 2^(2/12) = 1.1224620483... (A010768)
Minor third: 2^(3/12) = 1.1892071150... (A010767)
Major third: 2^(4/12) = 1.2599210498... (A002580)
Perfect fourth: 2^(5/12) = 1.3348398541... (this sequence)
Aug. fourth/
Dim. fifth: 2^(6/12) = 1.4142135623... (A002193)
Perfect fifth: 2^(7/12) = 1.4983070768... (A328229)
Minor sixth: 2^(8/12) = 1.5874010519... (A005480)
Major sixth: 2^(9/12) = 1.6817928305... (A011006)
Minor seventh: 2^(10/12) = 1.7817974362... (A329219)
Major seventh: 2^(11/12) = 1.8877486253... (A329220)
Perfect octave: 2^(12/12) = 2.0000000000

Programs

  • Mathematica
    First[RealDigits[2^(5/12), 10, 100]] (* Paolo Xausa, Apr 28 2024 *)
  • PARI
    default(realprecision, 100); 2^(5/12)

Formula

Equals 2/A328229.

A329220 Decimal expansion of 2^(11/12).

Original entry on oeis.org

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

Views

Author

Jianing Song, Nov 08 2019

Keywords

Comments

2^(11/12) is the ratio of the frequencies of the pitches in a major seventh (e.g., D4-C#5) in 12-tone equal temperament.

Crossrefs

Frequency ratios of musical intervals:
Perfect unison: 2^(0/12) = 1.0000000000
Minor second: 2^(1/12) = 1.0594630943... (A010774)
Major second: 2^(2/12) = 1.1224620483... (A010768)
Minor third: 2^(3/12) = 1.1892071150... (A010767)
Major third: 2^(4/12) = 1.2599210498... (A002580)
Perfect fourth: 2^(5/12) = 1.3348398541... (A329216)
Aug. fourth/
Dim. fifth: 2^(6/12) = 1.4142135623... (A002193)
Perfect fifth: 2^(7/12) = 1.4983070768... (A328229)
Minor sixth: 2^(8/12) = 1.5874010519... (A005480)
Major sixth: 2^(9/12) = 1.6817928305... (A011006)
Minor seventh: 2^(10/12) = 1.7817974362... (A329219)
Major seventh: 2^(11/12) = 1.8877486253... (this sequence)
Perfect octave: 2^(12/12) = 2.0000000000

Programs

  • Mathematica
    First[RealDigits[2^(11/12), 10, 100]] (* Paolo Xausa, Apr 28 2024 *)
  • PARI
    default(realprecision, 100); 2^(11/12)

Formula

Equals 2/A010774.
Equals Product_{k>=0} (1 + (-1)^k/(12*k + 1)). - Amiram Eldar, Jul 29 2020

A271836 Decimal expansion of 3^(1/3) / 2^(1/6).

Original entry on oeis.org

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

Views

Author

Wesley Ivan Hurt, Apr 15 2016

Keywords

Comments

Used in a formula for a regular octahedron, a = 3^(1/3)/2^(1/6) * V^(1/3), where a is the edge length and V^(1/3) is the cube root of the volume.
An algebraic number of degree 6 and denominator 2; minimal polynomial is 2x^6 - 9. - Charles R Greathouse IV, Apr 18 2016

Examples

			1.2848982934253252956716...
		

Crossrefs

Programs

  • Maple
    Digits:=100: evalf(3^(1/3)/2^(1/6));
  • Mathematica
    RealDigits[N[3^(1/3)/2^(1/6), 100]]
  • PARI
    3^(1/3) / 2^(1/6) \\ Altug Alkan, Apr 15 2016
    
  • PARI
    sqrtn(9/2,6) \\ Charles R Greathouse IV, Apr 18 2016

Formula

Equals A002581 / A010768.
Showing 1-6 of 6 results.