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.

A160386 Decimal expansion of Sum_{n>=0}(-1)^n/3^(2^n).

Original entry on oeis.org

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

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Author

Harry J. Smith, May 12 2009

Keywords

Comments

This sum is among forms which Kempner showed are transcendental. - Kevin Ryde, Sep 16 2019

Examples

			0.234415508674864614413415474345604597614724563906693027679427737098381...
		

Crossrefs

Cf. A006467 (continued fraction), A030300 (ternary expansion).

Programs

  • Mathematica
    RealDigits[N[Sum[(-1)^n/3^(2^n), {n, 0, Infinity}], 120]][[1]] (* Amiram Eldar, Jun 11 2023 *)
  • PARI
    { default(realprecision, 20080); x=10*suminf(n=0, (-1)^n/3^(2^n)); for (n=0, 20000, d=floor(x); x=(x-d)*10; write("b160386.txt", n, " ", d)); }