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.

A190281 Decimal expansion of (1+sqrt(1+r))/r, where r=sqrt(2).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, May 07 2011

Keywords

Comments

The rectangle R whose shape (i.e., length/width) is (1+sqrt(1+r))/r, where r=sqrt(2), can be partitioned into rectangles of shapes sqrt(2) and 2 in a manner that matches the periodic continued fraction [r, 2, r, 2, ...]. R can also be partitioned into squares so as to match the nonperiodic continued fraction [1,1,4,6,1,2,2,2,1,1 ...] at A190282. For details, see A188635.

Examples

			1.805790894654357490440645557345527417829...
		

Crossrefs

Programs

  • Magma
    (1 + Sqrt(1 + Sqrt(2)))/Sqrt(2); // G. C. Greubel, Jan 31 2018
  • Mathematica
    r=2^(1/2)
    FromContinuedFraction[{r,2, {r,2}}]
    FullSimplify[%]
    ContinuedFraction[%, 100]  (* A190282 *)
    RealDigits[N[%%, 120]]     (* A190281 *)
    N[%%%, 40]
    RealDigits[(1 + Sqrt[1 + Sqrt[2]])/Sqrt[2], 10, 100][[1]] (* G. C. Greubel, Jan 31 2018 *)
  • PARI
    (1 + sqrt(1 + sqrt(2)))/sqrt(2) \\ G. C. Greubel, Jan 31 2018