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 1-3 of 3 results.

A019851 Decimal expansion of sine of 42 degrees.

Original entry on oeis.org

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

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Author

N. J. A. Sloane

Keywords

Comments

This sequence is also decimal expansion of cosine of 48 degrees. - Mohammad K. Azarian, Jun 29 2013
A quartic number with denominator 2. - Charles R Greathouse IV, Nov 05 2017

Examples

			0.6691306...

Links

Crossrefs

Cf. A019857, A019887, A019830, A019878.

Programs

Formula

Equals cos(4*Pi/15) = (sqrt(5)-1)*(sqrt(3)*sqrt(5+2*sqrt(5))-1)/8 = 8*A019887^4 -8*A019887^2 + 1 = sqrt(1-A019857^2). - R. J. Mathar, Jun 18 2006
Equals 2*A019830*A019878. - R. J. Mathar, Jan 17 2021
A root of 16*x^4-8*x^3-16*x^2+8*x+1 =0. - R. J. Mathar, Aug 31 2025

A019872 Decimal expansion of sine of 63 degrees.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane

Keywords

Comments

An algebraic number of degree 8 and denominator 2. - Charles R Greathouse IV, Nov 06 2017

Links

Programs

Formula

Equals A019851 * A019878 + A019830 * A019857 = A010527 * A019896 + A019812 * (1/2). - R. J. Mathar, Jan 27 2021
This^2 + A019836^2=1. - R. J. Mathar, Aug 31 2025
One of the 8 real-valued roots of 256*x^8-512*x^6+304*x^4-48*x^2+1=0. (Other A019890, A019836, A019818) - R. J. Mathar, Aug 31 2025

A019967 Decimal expansion of tangent of 69 degrees.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane

Keywords

Comments

Also the decimal expansion of cotangent of 21 degrees. - Ivan Panchenko, Sep 01 2014

Examples

			2.605089064693801536258412336433541186093287267943195023752...

Links

Crossrefs

Cf. A019878 (sine of 69 degrees).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); Tan(23*Pi(R)/60); // G. C. Greubel, Nov 21 2018
  • Mathematica
    RealDigits[Tan[23*Pi/60], 10, 100][[1]] (* G. C. Greubel, Nov 20 2018 *)
  • PARI
    default(realprecision, 100); tan(23*Pi/60) \\ G. C. Greubel, Nov 21 2018
  • Sage
    numerical_approx(tan(23*pi/60), digits=100) # G. C. Greubel, Nov 21 2018
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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