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.

A199814 Decimal expansion of x value of the unique pairwise intersection on (0,1) of distinct order 5 power tower functions with parentheses inserted.

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Nov 10 2011

Keywords

Comments

Order 5 is the smallest order such that pairwise intersections on (0,1) of distinct power tower functions with parentheses inserted exist. The corresponding y value is 0.66337467860163682654502... . The two intersecting functions are x-> (x^(x^x))^(x^x) and x-> x^(x^((x^x)^x)).

Examples

			0.42801103796472992390204...
		

Crossrefs

Cf. A000081 (number of distinct power tower functions), A000108 (number of parenthesizations), A199879 (continued fraction), A199880 (Engel expansion).

Programs

  • Maple
    f:= x-> (x^(x^x))^(x^x): g:= x-> x^(x^((x^x)^x)):
    nmax:= 140: Digits:= nmax+10:
    xv:= fsolve(f(x)=g(x), x=0..0.99):
    s:= convert(xv, string):
    seq(parse(s[n+2]), n=0..nmax);
  • Mathematica
    x /. FindRoot[x^(x^2) - 2*x == 0, {x, 1/2}, WorkingPrecision -> 110] // RealDigits[#, 10, 105]& // First (* Jean-François Alcover, Dec 05 2013 *)

Formula

x in (0,1) : x^(x^2)-2*x = 0.

A199879 Continued fraction for x value of the unique pairwise intersection on (0,1) of distinct order 5 power tower functions with parentheses inserted.

Original entry on oeis.org

0, 2, 2, 1, 35, 1, 2, 2, 1, 2, 5, 3, 1, 1, 45, 1, 1, 6, 11, 2, 9, 2, 2, 2, 2, 1, 1, 1, 29, 1, 3, 7, 4, 1, 7, 61, 1, 1, 2, 1, 2, 6, 2, 1, 1, 96, 11, 1, 2, 1, 1, 4, 14, 1, 10, 1, 2, 1, 7, 4, 7, 5, 10, 1, 6, 2, 2, 9, 6, 8, 3, 1, 3, 1, 3, 7, 9
Offset: 0

Views

Author

Alois P. Heinz, Nov 11 2011

Keywords

Examples

			0.42801103796472992390204...
		

Crossrefs

Cf. A199814 (decimal expansion), A199880 (Engel expansion).

Programs

  • Maple
    with(numtheory):
    f:= x-> (x^(x^x))^(x^x): g:= x-> x^(x^((x^x)^x)):
    Digits:= 200:
    xv:= fsolve(f(x)=g(x), x=0..0.99):
    cfrac(evalf(xv), 120, 'quotients')[];
  • Mathematica
    terms = 77; digits = terms+10; xv = x /. FindRoot[x^(x^2) - 2x == 0, {x, 1/2}, WorkingPrecision -> digits]; ContinuedFraction[xv, terms] (* Jean-François Alcover, Mar 24 2017 *)

Extensions

Offset changed by Andrew Howroyd, Jul 03 2024
Showing 1-2 of 2 results.