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.

A087046 Algebraic order of r_n, the value of r in the logistic map that corresponding to the onset of the period 2^n-cycle.

Original entry on oeis.org

1, 2, 12, 240, 65280, 4294901760, 18446744069414584320, 340282366920938463444927863358058659840, 115792089237316195423570985008687907852929702298719625575994209400481361428480
Offset: 1

Views

Author

Eric W. Weisstein, Aug 04 2003

Keywords

Crossrefs

Cf. A051179 (partial sums).

Programs

  • Mathematica
    Table[If[n <= 1, 1, 2^(2^(n - 1)) - 2^(2^(n - 2))], {n, 1, 10}] (* Cheng Zhang, Apr 02 2012 *)
  • PARI
    a(n) = 1<<(1<<(n-1)) - 1<<(1<<(n-2)); \\ Kevin Ryde, Jan 18 2024

Formula

a(n) = 2^(2^(n - 1)) - 2^(2^(n - 2)) with n>1, a(1)=1. - Cheng Zhang, Apr 02 2012
Sum_{n>=1} 1/a(n) = 1 + A346192. - Amiram Eldar, Jul 18 2021

Extensions

More terms from Cheng Zhang, Apr 03 2012

A346190 Decimal expansion of Sum_{k>=0} 1/(2^(2^(2*k+1)) - 1).

Original entry on oeis.org

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

Views

Author

Amiram Eldar, Jul 09 2021

Keywords

Comments

This constant is transcendental (Schwarz, 1967).

Examples

			0.50781250046566128730773925781250000000587747175411...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sum[1/(2^(2^(2*n + 1) - 1)), {n, 0, 10}], 10, 100][[1]]

Formula

Equals A076214 - A346191.

A346191 Decimal expansion of Sum_{k>=0} 1/(2^(2^(2*k)) - 1).

Original entry on oeis.org

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

Views

Author

Amiram Eldar, Jul 09 2021

Keywords

Comments

This constant is transcendental (Schwarz, 1967).

Examples

			1.12503051757812500010842021724855044340074528008699...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sum[1/(2^(2^(2*n) - 1)), {n, 0, 10}], 10, 100][[1]]

Formula

Equals A076214 - A346190.
Showing 1-3 of 3 results.