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.

A078890 Decimal expansion of Sum {n>=0} 1/9^(2^n).

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Dec 11 2002

Keywords

Examples

			0.123609229144306327782...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[ N[ Sum[1/9^(2^n), {n, 0, Infinity}], 110]][[1]]
  • PARI
    suminf(n=0, 1/9^(2^n)) \\ Michel Marcus, Nov 11 2020

Formula

Equals A078885 - 1/3 = A078885 - A010701. - R. J. Mathar, Apr 23 2009
Equals -Sum_{k>=1} mu(2*k)/(9^k - 1), where mu is the Möbius function (A008683). - Amiram Eldar, Jul 12 2020