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.

A197733 Decimal expansion of 2*Pi/(1+Pi).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 17 2011

Keywords

Comments

Least x>0 such that sin(bx)=cos(cx) (and also sin(cx)=cos(bx)), where b=1/4 and c=Pi/4; see the Mathematica program for a graph and A197682 for a discussion and guide to related sequences.
Equals the harmonic mean of 1 and Pi. - Stanislav Sykora, Apr 11 2016

Examples

			1.51709398598955229068886137808978572827685273...
		

Crossrefs

Cf. A074950 (harmonic mean of Pi and e), A197682.

Programs

  • MATLAB
    2*pi/(1+pi) % Altug Alkan, Apr 11 2016
  • Mathematica
    b = 1/4; c = Pi/4;
    t = x /. FindRoot[Sin[b*x] == Cos[c*x], {x, 1.517, 1.518}]
    N[Pi/(2*b + 2*c), 110]
    RealDigits[%]  (* A197733 *)
    Simplify[Pi/(2*b + 2*c)]
    Plot[{Sin[b*x], Cos[c*x]}, {x, 0, Pi/2}]
    RealDigits[2Pi/(1+Pi),10,120][[1]] (* Harvey P. Dale, Jun 17 2022 *)
  • PARI
    2*Pi/(1+Pi) \\ Michel Marcus, Apr 11 2016
    

A074951 Continued fraction for harmonic mean of Pi and e.

Original entry on oeis.org

2, 1, 10, 1, 2, 1, 1, 10, 1, 1, 2, 1, 11, 1, 5, 1, 1, 7, 58, 3, 1, 2, 2, 7, 13, 3, 1, 20, 1, 20, 1, 2, 8, 2, 1, 1, 2, 1, 1, 14, 3, 4, 1, 1, 1, 1, 8, 1, 6, 4, 1, 3, 1, 2, 2, 1, 1, 12, 42, 9, 1, 1, 1, 1, 6, 1, 1, 3, 8, 2, 7, 1, 1, 2, 2, 1, 1, 3, 1, 17, 1, 3, 2, 4, 1, 2, 1, 4, 3, 1, 1, 1, 7, 13, 22, 1, 2
Offset: 0

Views

Author

Zak Seidov, Oct 05 2002

Keywords

Crossrefs

Cf. A074950 (decimal expansion).

Programs

  • Mathematica
    ContinuedFraction[HarmonicMean[{Pi,E}],100] (* Harvey P. Dale, May 16 2013 *)

Extensions

Offset changed by Andrew Howroyd, Jul 06 2024

A342209 Decimal expansion of logarithmic mean of Pi and e.

Original entry on oeis.org

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

Views

Author

Gleb Koloskov, Mar 05 2021

Keywords

Comments

The logarithmic mean of Pi and e lies between the arithmetic and geometric means of Pi and e.

Examples

			2.9248335452376948992733592...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(Pi - E)/(Log[Pi] - 1), 10, 100][[1]] (* Amiram Eldar, Mar 06 2021 *)
  • PARI
    (Pi-exp(1))/(log(Pi)-1)

Formula

Equals (Pi-e)/(log(Pi)-1).
Showing 1-3 of 3 results.