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.

A190184 Decimal expansion of sqrt(1+x+sqrt(1+2*x)), where x=sqrt(2/3).

Original entry on oeis.org

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

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Author

Clark Kimberling, May 05 2011

Keywords

Comments

The rectangle R whose shape (i.e., length/width) is sqrt(1+x+sqrt(1+2x)), where x=sqrt(2/3), can be partitioned into rectangles of shapes sqrt(2) and sqrt(3) in a manner that matches the periodic continued fraction [sqrt(2), sqrt(3), sqrt(2), sqrt(3),...]. R can also be partitioned into squares so as to match the nonperiodic continued fraction [1,1,5,1,6,1,5,1,1,...] at A190185. For details, see A188635.

Examples

			1.854493630042558263683640132452778477778...
		

Crossrefs

Cf. A190185.

Programs

  • Magma
    [Sqrt(1+Sqrt(2/3)+Sqrt(1+2*Sqrt(2/3)))]; // G. C. Greubel, Dec 28 2017
  • Mathematica
    FromContinuedFraction[{2^(1/2), 3^(1/2), {2^(1/2), 3^(1/2)}}]
    FullSimplify[%]
    ContinuedFraction[%, 100]  (* A190185 *)
    RealDigits[N[%%, 120]]      (* A190186 *)
    N[%%%, 40]
    RealDigits[Sqrt[1+Sqrt[2/3]+Sqrt[1+2*Sqrt[2/3]]], 10, 100][[1]] (* G. C. Greubel, Dec 28 2017 *)
  • PARI
    sqrt(1+sqrt(2/3)+sqrt(1+2*sqrt(2/3))) \\ G. C. Greubel, Dec 28 2017
    

Extensions

Definition corrected by Bruno Berselli, May 13 2011