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.

A200015 Decimal expansion of greatest x satisfying x^2 - cos(x) = 3*sin(x).

Original entry on oeis.org

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

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Author

Clark Kimberling, Nov 12 2011

Keywords

Comments

See A199949 for a guide to related sequences. The Mathematica program includes a graph.

Examples

			least x:  -0.2943487723356863983696578902036195...
greatest x: 1.690779738969815334957504857558809...
		

Crossrefs

Cf. A199949.

Programs

  • Mathematica
    a = 1; b = -1; c = 3;
    f[x_] := a*x^2 + b*Cos[x]; g[x_] := c*Sin[x]
    Plot[{f[x], g[x]}, {x, -1, 2}, {AxesOrigin -> {0, 0}}]
    r = x /. FindRoot[f[x] == g[x], {x, -.3, -.29}, WorkingPrecision -> 110]
    RealDigits[r]  (* A200014 *)
    r = x /. FindRoot[f[x] == g[x], {x, 1.6, 1.7}, WorkingPrecision -> 110]
    RealDigits[r]   (* A200015 *)
  • PARI
    a=1; b=-1; c=3; solve(x=1, 2, a*x^2 + b*cos(x) - c*sin(x)) \\ G. C. Greubel, Jun 23 2018

Extensions

a(88)-a(99) corrected by G. C. Greubel, Jun 23 2018