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.

A343786 Decimal expansion of Sum_{k>=0} 2^(3^k)/(2^(2*(3^k)) + 2^(3^k) + 1).

Original entry on oeis.org

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

Views

Author

Amiram Eldar, Apr 29 2021

Keywords

Comments

Proven to be a transcendental number by Borwein and Coons (2008).

Examples

			0.39725264457801453528444061025296764648419265353335...
		

Crossrefs

Programs

  • Mathematica
    f[x_] := x/(x^2 + x + 1); RealDigits[Sum[f[2^(3^n)], {n, 0, 10}], 10, 100][[1]]

Formula

Equals Sum_{k>=1} A343785(k)/2^k.