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.

A188726 Continued fraction of the shape of a (2*Pi)-extension rectangle; shape = Pi + sqrt(1 + Pi^2).

Original entry on oeis.org

6, 2, 3, 1, 1, 3, 2, 1, 16, 47, 1, 4, 2, 7, 1, 5, 317, 4, 1, 1, 1, 2, 13, 1, 38, 37, 1, 4, 1, 13, 1, 59, 3, 17, 1, 2, 2, 2, 5, 1, 3, 1, 3, 9, 1, 3, 4, 1, 2, 2, 1, 1, 2, 1, 23, 8, 9, 84, 1, 3, 1, 2, 1, 1, 3, 5, 5, 1, 1, 16, 1, 8, 4, 11, 1, 3, 1, 16, 4, 1, 1, 1, 1, 18, 1, 12, 1, 21, 3, 3, 1, 2, 4, 2, 10, 3, 5, 6, 1, 1, 25, 4, 10, 1, 5, 2, 1, 4, 16, 2, 5, 4, 2, 1, 4, 1, 1, 2, 1, 1
Offset: 0

Views

Author

Clark Kimberling, Apr 09 2011

Keywords

Comments

See A188640 for definitions of shape and r-extension rectangle. Briefly, an r-extension rectangle is composed of two rectangles of shape r.
A 2*Pi-extension rectangle matches the continued fraction [6,2,3,1,1,3,2,1,16,47,...] of the shape L/W = Pi + sqrt(1 + Pi^2). This is analogous to the matching of a golden rectangle to the continued fraction [1,1,1,1,1,1,1,...]. Specifically, for the (2*Pi)-extension rectangle, 6 squares are removed first, then 2 squares, then 3 squares, then 1 square, then 1 square, ..., so that the original rectangle is partitioned into an infinite collection of squares.

Examples

			6.4385009630654083972232325635946917292621665408132...
		

Crossrefs

Cf. A188640, A188725 (decimal expansion).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); ContinuedFraction(Pi(R) + Sqrt(1 + Pi(R)^2)); // G. C. Greubel, Oct 31 2018
  • Maple
    with(numtheory): cfrac(Pi+sqrt(1+Pi^2),120,'quotients'); # Muniru A Asiru, Nov 22 2018
  • Mathematica
    r = 2*Pi; t = (r + (4 + r^2)^(1/2))/2; FullSimplify[t]
    N[t, 130]
    RealDigits[N[t, 130]][[1]] (* A188725 *)
    ContinuedFraction[t, 120] (* A188726 *)
    ContinuedFraction[Pi + Sqrt[1 + Pi^2], 100] (* G. C. Greubel, Oct 31 2018 *)
  • PARI
    default(realprecision, 100); contfrac(Pi + sqrt(1 + Pi^2)) \\ G. C. Greubel, Oct 31 2018
    

A188720 Decimal expansion of (e+sqrt(4+e^2))/2.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Apr 09 2011

Keywords

Comments

Decimal expansion of shape of an e-extension rectangle; see A188640 for definitions of shape and r-extension rectangle. Briefly, an r-extension rectangle is composed of two rectangles having shape r.
An e-extension rectangle matches the continued fraction A188721 of the shape L/W = (1/2) *(e+sqrt(4+e^2)). This is analogous to the matching of a golden rectangle to the continued fraction [1,1,1,1,1,1,1,...]. Specifically, for an e-extension rectangle, 3 squares are removed first, then 21 squares, then 2 squares, then 40 squares, then 1 square,..., so that the original rectangle is partitioned into an infinite collection of squares.
(e+sqrt(4+e^2))/2 = [e,e,e,... ] (continued fraction). - Clark Kimberling, Sep 23 2013

Examples

			3.046524695333472471811401766587155243274607058879794774577422496312...
		

Crossrefs

Programs

  • Magma
    SetDefaultRealField(RealField(100)); (Exp(1) +Sqrt(4+Exp(2)))/2; // G. C. Greubel, Oct 31 2018
  • Maple
    evalf((exp(1)+sqrt(4+exp(2)))/2,140); # Muniru A Asiru, Nov 01 2018
  • Mathematica
    r=E; t = (r + (4+r^2)^(1/2))/2; FullSimplify[t]
    N[t, 130]
    RealDigits[N[t, 130]][[1]]
    RealDigits[(E+Sqrt[4+E^2])/2,10,150][[1]] (* Harvey P. Dale, Jan 07 2015 *)
  • PARI
    default(realprecision, 100); (exp(1) + sqrt(4 + exp(2)))/2 \\ G. C. Greubel, Oct 31 2018
    

A360938 Decimal expansion of arcsinh(Pi).

Original entry on oeis.org

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

Views

Author

Wolfe Padawer, Feb 26 2023

Keywords

Examples

			1.862295743310848219888361325182620574902674184961554765612879514423...
		

References

  • Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 31, page 291.

Crossrefs

Programs

  • Mathematica
    RealDigits[ArcSinh[Pi], 10, 105][[1]]
  • PARI
    asinh(Pi) \\ Michel Marcus, Feb 26 2023

Formula

Equals log(Pi + sqrt(Pi^2 + 1)) = log(A188725).
Equals Pi*Integral_{x=0..1} 1/sqrt((Pi^2)*x^2 + 1) dx.
Showing 1-3 of 3 results.