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 1-2 of 2 results.

A190284 Continued fraction of 1+sqrt(1+sqrt(2)).

Original entry on oeis.org

2, 1, 1, 4, 6, 1, 2, 2, 2, 1, 1, 6, 1, 179, 46, 1, 1, 3, 2, 1, 1, 3, 6, 3, 1, 1, 1, 1, 2, 1, 1, 56, 1, 1, 1, 1, 66, 1, 1, 2, 17, 8, 2, 7, 12, 1, 1, 8, 1, 2, 2, 1, 1, 2, 1, 12, 1, 2, 2, 2, 2, 1, 1, 1, 8, 1, 1, 1, 1, 2, 1, 2, 5, 1, 6, 8, 1, 1, 1, 2, 7, 1, 9, 1, 2, 5, 7, 1, 6, 1, 10, 1, 2, 1, 3, 47, 1, 1, 998, 1
Offset: 1

Views

Author

Clark Kimberling, May 07 2011

Keywords

Comments

1

Crossrefs

Programs

  • Magma
    ContinuedFraction(1+Sqrt(1+Sqrt(2))); // G. C. Greubel, Apr 14 2018
  • Mathematica
    FromContinuedFraction[{2, Sqrt[2], {2, r}}]
    FullSimplify[%]
    ContinuedFraction[%, 100]  (* A190284 *)
    RealDigits[N[%%, 120]]     (* A190283 *)
  • PARI
    contfrac(1+sqrt(1+sqrt(2))) \\ G. C. Greubel, Apr 14 2018
    

A278928 Decimal expansion of sqrt(sqrt(2) + 1).

Original entry on oeis.org

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

Views

Author

Bobby Jacobs, Dec 01 2016

Keywords

Comments

A quartic integer with minimal polynomial x^4 - 2*x^2 - 1. - Charles R Greathouse IV, Dec 01 2016
Suppose f(n) has the recurrence f(2*n) = f(2*n - 1) + f(2*n - 2) and f(2*n + 1) = f(2*n) + f(2*n - 2), where f(0) and f(1) are not both 0. Then, lim_{n -> oo} f(n)^(1/n) is this constant.
Apart from the first digit, the same as A190283. - R. J. Mathar, Dec 09 2016
Imaginary part of sqrt(1 + i)^3, where i is the imaginary unit such that i^2 = -1. See A154747 for real part. - Alonso del Arte, Sep 09 2019

Examples

			1.553773974030037307344158953063146948164583499410307836332671...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 7.4, p. 466.

Crossrefs

Cf. A309948 and A309949 for real and imaginary parts of sqrt(1 + i).

Programs

Formula

Equals 1/A154747.
Limit_{n -> oo} A002965(n)^(1/n).
From Peter Bala, Jul 01 2024: (Start)
This constant occurs in the evaluation of Integral_{x = 0..Pi/2} 1/(1 + sin^4(x)) dx = Pi/4 * sqrt(sqrt(2) + 1).
Equals 2*Sum_{n >= 0} (-1/16)^n * binomial(4*n, 2*n) (a slowly converging series). (End)
Equals 2^(3/4)*cos(Pi/8). - Vaclav Kotesovec, Jul 01 2024
Equals Product_{k>=0} coth(Pi/4 + k*Pi/2). - Antonio GraciĆ” Llorente, Dec 19 2024
Equals sqrt(A014176) = 1/A154747 = exp(A245592). - Hugo Pfoertner, Dec 19 2024
Showing 1-2 of 2 results.