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 1-10 of 16 results. Next

A197003 Decimal expansion of the slope of the line y=mx which meets the curve y=cos(x+Pi/4) orthogonally over the interval [0, 2*Pi] (as in A197002).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 09 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=0.3695425666075803208276560438369...
yo=0.4039727532995172093189617400663...
m=1.09316974498501692208815321416057...
|OP|=0.54749949218543621432520415035...

Crossrefs

Programs

  • Mathematica
    c = Pi/4;
    xo = x /. FindRoot[x == Sin[x + c] Cos[x + c], {x, .8, 1.2}, WorkingPrecision -> 100]
    RealDigits[xo] (* A197002 *)
    m = 1/Sin[xo + c]
    RealDigits[m]  (* A197003 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{Cos[x + c], yo - (1/m) (x - xo)}, {x, -Pi/4, 1}], ContourPlot[{y == m*x}, {x, 0, Pi}, {y, 0, 1}], PlotRange -> All, AspectRatio -> Automatic, AxesOrigin -> Automatic]
  • PARI
    my(d=solve(x=0,1,cos(x)-x)); sqrt(2-2*sqrt(1-d^2))/d \\ Gleb Koloskov, Jun 16 2021

Formula

Equals sqrt(2-2*sqrt(1-d^2))/d where d = A003957. - Gleb Koloskov, Jun 16 2021

A003957 The Dottie number: decimal expansion of root of cos(x) = x.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

Let P be the point in quadrant I where the curve y=sin(x) meets the circle x^2+y^2=1. Let d be the Dottie number. Then P=(d,sin(d)), and d is the slope at P of the sine curve. - Clark Kimberling, Oct 07 2011
From Ben Branman, Dec 28 2011: (Start)
The name "Dottie" is of no fundamental mathematical significance since it refers to a particular French professor who--no doubt like many other calculator users before and after her--noticed that whenever she typed a number into her calculator and hit the cosine button repeatedly, the result always converged to this value.
The number is well-known, having appeared in numerous elementary works on algebra already by the late 1880s (e.g., Bertrand 1865, p. 285; Heis 1886, p. 468; Briot 1881, pp. 341-343), and probably much earlier as well. It is also known simply as the cosine constant, cosine superposition constant, iterated cosine constant, or cosine fixed point constant. Arakelian (1981, pp. 135-136; 1995) has used the Armenian small letter ayb (ա, the first letter in the Armenian alphabet) to denote this constant. (End)

Examples

			0.73908513321516064165531208767387340401341175890075746496568063577328...
		

References

  • H. Arakelian, The Fundamental Dimensionless Values (Their Role and Importance for the Methodology of Science). [In Russian.] Yerevan, Armenia: Armenian National Academy of Sciences, 1981.
  • A. Baker, Theorem 1.4 in Transcendental Number Theory. Cambridge, England: Cambridge University Press, 1975.

Crossrefs

Cf. A330119 (degrees-based analog).

Programs

  • Maple
    evalf(solve(cos(x)=x,x), 140);  # Alois P. Heinz, Feb 20 2024
  • Mathematica
    RealDigits[ FindRoot[ Cos[x] == x, {x, {.7, 1} }, WorkingPrecision -> 120] [[1, 2] ]] [[1]]
    FindRoot[Cos[x] == x, {x, {.7, 1}}, WorkingPrecision -> 500][[1, 2]][[1]] (* Ben Branman, Apr 12 2008 *)
    N[NestList[Cos, 1, 100], 20] (* Clark Kimberling, Jul 01 2019 *)
    RealDigits[Root[{# - Cos[#] &, 0.739085}], 10, 100][[1]] (* Eric W. Weisstein, Jul 15 2022 *)
    RealDigits[Sqrt[1 - (2 InverseBetaRegularized[1/2, 1/2, 3/2] - 1)^2], 10, 100][[1]] (* Eric W. Weisstein, Jul 15 2022 *)
  • PARI
    solve(x=0,1,cos(x)-x) \\ Charles R Greathouse IV, Dec 31 2011
    
  • Python
    from sympy import Symbol, nsolve, cos
    x = Symbol("x")
    a = list(map(int, str(nsolve(cos(x)-x, 1, prec=110))[2:-2]))
    print(a) # Michael S. Branicky, Jul 15 2022

Formula

Equals twice A197002. - Hugo Pfoertner, Feb 20 2024

Extensions

More terms from David W. Wilson
Additional references from Ben Branman, Dec 28 2011

A196996 Decimal expansion of xo, where P=(xo,yo) is the point nearest O=(0,0) at which a line y=m*x meets the curve y=cos(3x) orthogonally.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 09 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=0.9350272884749678361451944275323...
yo=0.3301955980451199836007253971727...
m=0.35314006565912096755666111412785...
|OP|=0.99161744799152518925689622748...

Crossrefs

Programs

  • Mathematica
    c = 3;
    xo = x /. FindRoot[0 == x + c*Sin[c*x] Cos[c*x], {x, .8, 1.2}, WorkingPrecision -> 100]
    RealDigits[xo] (* A196996 *)
    m = Sin[c*xo]/xo
    RealDigits[m]  (* A196997 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{Sin[c*x], yo - (1/m) (x - xo)}, {x, 0, Pi/c}], ContourPlot[{y == m*x}, {x, 0, 1.5}, {y, -.1, 1}], PlotRange -> All, AspectRatio -> Automatic]

A197000 Decimal expansion of xo, where P=(xo,yo) is the point nearest O=(0,0) in which a line y=mx meets the curve y=1+cos(x) orthogonally.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 09 2011

Keywords

Comments

See the Mathematica program for a graph.

Examples

			xo=1.2488014367215508560475125020128381535587614... <------ this constant
yo=1.3164595537507515212878992732671186100622603...
m=1.05417844265684217515747734305673483746142104...
|OP|=1.81454423617045980814297669595599066552030...
		

Crossrefs

Programs

  • Mathematica
    c = 1;
    xo = x /.
      FindRoot[x == Sin[x] (c + Cos[x]), {x, 1, 1.3}, WorkingPrecision -> 100]
    RealDigits[xo] (* A197000 *)
    m = 1/Sin[xo]
    RealDigits[m]  (* A197001 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{c + Cos[c*x], yo - (1/m) (x - xo)}, {x, 0, Pi}],  ContourPlot[{y == m*x}, {x, 0, Pi}, {y, 0, 2}], PlotRange -> All, AspectRatio -> Automatic, AxesOrigin -> Automatic]
  • PARI
    solve(x=1,2, sin(x)*(cos(x)+1)-x) \\ Charles R Greathouse IV, Feb 03 2025

A196997 Decimal expansion of m, where y=m*x is the line through (0,0) which meets the curve y=cos(3*x) orthogonally at a point (x,y) satisfying 0 < x < 2*Pi.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 09 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=0.9350272884749678361451944275323...
yo=0.3301955980451199836007253971727...
m=0.35314006565912096755666111412785...
|OP|=0.99161744799152518925689622748...

Crossrefs

Programs

  • Mathematica
    c = 3;
    xo = x /. FindRoot[0 == x + c*Sin[c*x] Cos[c*x], {x, .8, 1.2}, WorkingPrecision -> 100]
    RealDigits[xo] (* A196996 *)
    m = Sin[c*xo]/xo
    RealDigits[m]  (* A196997 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{Sin[c*x], yo - (1/m) (x - xo)}, {x, 0, Pi/c}], ContourPlot[{y == m*x}, {x, 0, 1.5}, {y, -.1, 1}], PlotRange -> All, AspectRatio -> Automatic]

A197006 Decimal expansion of xo, where P=(xo,yo) is the point nearest O=(0,0) in which a line y=mx meets the curve y=cos(x+Pi/6) orthogonally.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 10 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=0.460885580860965976987981282513698...
yo=0.553292712300593256734925495541442...
m=1.2004990723879979061250465124427113...
|OP|=0.7201030093885853693640956082816...

Crossrefs

Programs

  • Mathematica
    c = Pi/6;
    xo = x /.  FindRoot[x == Sin[x + c] Cos[x + c], {x, .8, 1.2}, WorkingPrecision -> 100]
    RealDigits[xo] (* A197006 *)
    m = 1/Sin[xo + c]
    RealDigits[m] (* A197007 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{Cos[x + c], yo - (1/m) (x - xo)}, {x, -Pi/4, Pi/2}], ContourPlot[{y == m*x}, {x, 0, Pi}, {y, 0, 1}], PlotRange -> All,
    AspectRatio -> Automatic, AxesOrigin -> Automatic]

A196998 Decimal expansion of xo, where P=(xo,yo) is the point nearest O=(0,0) at which a line y=m*x meets the curve y=cos(5x/2) orthogonally.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 09 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=1.055537135075475249854148417892290354122...
yo=0.481836913462240473673427172075977637742...
m=0.4564850420234501281397606474354137170643...
|OP|=1.1603126538559168441096914160911620183...

Crossrefs

Programs

  • Mathematica
    c = 5/2;
    xo = x /.  FindRoot[0 == x + c*Sin[c*x] Cos[c*x], {x, .8, 1.2}, WorkingPrecision -> 100]
    RealDigits[xo] (* A196998 *)
    m = Sin[c*xo]/xo
    RealDigits[m]  (* A196999 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{Sin[c*x], yo - (1/m) (x - xo)}, {x, 0, Pi/c}],
     ContourPlot[{y == m*x}, {x, 0, Pi/c}, {y, -.1, 1}], PlotRange -> All, AspectRatio -> Automatic]

A196999 Decimal expansion of slope of the line y=mx which meets the curve y=cos(5x/2) orthogonally (as in A196998).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 09 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=1.055537135075475249854148417892290354122...
yo=0.481836913462240473673427172075977637742...
m=0.4564850420234501281397606474354137170643...
|OP|=1.1603126538559168441096914160911620183...

Crossrefs

Programs

  • Mathematica
    c = 5/2;
    xo = x /.  FindRoot[0 == x + c*Sin[c*x] Cos[c*x], {x, .8, 1.2}, WorkingPrecision -> 100]
    RealDigits[xo] (* A196998 *)
    m = Sin[c*xo]/xo
    RealDigits[m]  (* A196999 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{Sin[c*x], yo - (1/m) (x - xo)}, {x, 0, Pi/c}],
     ContourPlot[{y == m*x}, {x, 0, Pi/c}, {y, -.1, 1}], PlotRange -> All, AspectRatio -> Automatic]

A197001 Decimal expansion of the slope of the line y=mx which meets the curve y=1+cos(x) orthogonally over the interval [0, 2*Pi] (as in A197000).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 09 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=1.2488014367215508560475125020128381535587614...
yo=1.3164595537507515212878992732671186100622603...
m=1.05417844265684217515747734305673483746142104...
|OP|=1.81454423617045980814297669595599066552030...

Crossrefs

Programs

  • Mathematica
    c = 1;
    xo = x /.
      FindRoot[x == Sin[x] (c + Cos[x]), {x, 1, 1.3}, WorkingPrecision -> 100]
    RealDigits[xo] (* A197000 *)
    m = 1/Sin[xo]
    RealDigits[m]  (* A197001 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{c + Cos[c*x], yo - (1/m) (x - xo)}, {x, 0, Pi}],  ContourPlot[{y == m*x}, {x, 0, Pi}, {y, 0, 2}], PlotRange -> All, AspectRatio -> Automatic, AxesOrigin -> Automatic]

A197004 Decimal expansion of xo, where P=(xo,yo) is the point nearest O=(0,0) in which a line y=mx meets the curve y=cos(x+Pi/3) orthogonally.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Oct 10 2011

Keywords

Comments

See the Mathematica program for a graph.
xo=0.255465286103853596695882696613320272654788...
yo=0.264932084602776862434116494762571068650190...
m=1.0370570837365150046614795837584277605222343...
|OP|=0.3680373919265496189530095416155881110455...

Crossrefs

Programs

  • Mathematica
    c = Pi/3;
    xo = x /. FindRoot[x == Sin[x + c] Cos[x + c], {x, .8, 1.2}, WorkingPrecision -> 100]
    RealDigits[xo] (* A197004 *)
    m = 1/Sin[xo + c]
    RealDigits[m]  (* A197005 *)
    yo = m*xo
    d = Sqrt[xo^2 + yo^2]
    Show[Plot[{Cos[x + c], yo - (1/m) (x - xo)}, {x, -Pi/4, Pi/2}],
    ContourPlot[{y == m*x}, {x, 0, Pi}, {y, 0, 1}], PlotRange -> All,
    AspectRatio -> Automatic, AxesOrigin -> Automatic]
Showing 1-10 of 16 results. Next