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.

A197376 Decimal expansion of least x>0 having sin(x)=(sin (x/2))^2.

Original entry on oeis.org

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

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Author

Clark Kimberling, Oct 14 2011

Keywords

Comments

The Mathematica program includes a graph. See A197133 for a guide to least x>0 satisfying sin(b*x)=(sin(c*x))^2 for selected b and c.

Examples

			2.2142974355881810060341309203570740...
		

Crossrefs

Cf. A197133.

Programs

  • Mathematica
    b = 1; c = 1/2; f[x_] := Sin[x]
    t = x /. FindRoot[f[b*x] == f[c*x]^2, {x, 2, 2.5}, WorkingPrecision -> 200]
    RealDigits[t] (*  *)
    Plot[{f[b*x], f[c*x]^2}, {x, 0, 2.5}]
    RealDigits[ 2*ArcCos[ 1/Sqrt[5] ], 10, 99] // First (* Jean-François Alcover, Feb 19 2013 *)

Formula

Equals 2*A105199. - R. J. Mathar, Aug 27 2024