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 1-3 of 3 results.

A185262 Decimal expansion of 2^(1/phi).

Original entry on oeis.org

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

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    RealDigits[N[2^(1/GoldenRatio),200]][[1]]
  • PARI
    2^((sqrt(5)-1)/2) \\ Charles R Greathouse IV, Oct 01 2012

A335020 Decimal expansion of (1/phi)^(1/phi), where phi is the golden ratio (1 + sqrt(5))/2 (A001622).

Original entry on oeis.org

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

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Author

Alois P. Heinz, May 19 2020

Keywords

Comments

The real function f(x) = (1/phi)^(1/phi) x^phi satisfies the differential equation f'(x) = f^(-1)(x): the derivative of f equals the compositional inverse of f.

Examples

			0.7427429446246816413695660476057885141497552527...
		

Crossrefs

Programs

  • Maple
    g:= (phi-> (1/phi)^(1/phi))((1+sqrt(5))/2):
    evalf(g, 140);
  • Mathematica
    RealDigits[(1/GoldenRatio)^(1/GoldenRatio), 10, 100][[1]] (* Amiram Eldar, May 21 2020 *)
  • PARI
    my(x=(sqrt(5)-1)/2); x^x \\ Michel Marcus, May 21 2020

Formula

Equals (phi-1)^(phi-1), with phi = (1 + sqrt(5))/2.

A348359 Decimal expansion of the nontrivial number x for which x^phi = phi^x, where phi is the golden ratio (1+sqrt(5))/2.

Original entry on oeis.org

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

Views

Author

Timothy L. Tiffin, Oct 14 2021

Keywords

Comments

The x-th root of x equals the phi-th root of phi: x^(1/x) = phi^(1/phi) = A185261 = 1.3463608200348694434247534661858... .
Not surprisingly, x appears to be irrational. If x is also algebraic, then x^phi would be transcendental by the Gelfond-Schneider theorem.

Examples

			6.055722091024741002126639117583149731683828...
x^phi = phi^x  = 18.431940924839652158136364051482054378959672... .
		

Crossrefs

Cf. A001622 (phi), A094214 (1/phi), A185261 (phi^(1/phi)), A073226 (e^e, see first comment).

Programs

  • Mathematica
    RealDigits[x/.FindRoot[x^GoldenRatio==GoldenRatio^x,{x,6},WorkingPrecision->120],10,120][[1]] (* Harvey P. Dale, Dec 09 2024 *)

Extensions

Prior Mathematica program replaced by Harvey P. Dale, Dec 09 2024
Showing 1-3 of 3 results.