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.

A124091 Decimal expansion of Fibonacci binary constant: Sum{i>=0} (1/2)^Fibonacci(i).

Original entry on oeis.org

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

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Author

R. J. Mathar, Nov 25 2006

Keywords

Comments

This constant is transcendental, see A084119. - Charles R Greathouse IV, Nov 12 2014

Examples

			2.4102787972078658917940430244710631444834239245952787725932...
		

Crossrefs

Cf. A007404 (Kempner-Mahler number), A125600 (continued fraction), A084119 (essentially the same).
Cf. A000301.

Programs

  • Mathematica
    RealDigits[ N[ Sum[(1/2)^Fibonacci[i], {i, 0, Infinity}], 111]][[1]] (* Robert G. Wilson v, Nov 26 2006 *)
  • PARI
    a=0 ; for(n=0,30, a += .5^fibonacci(n) ; print(a) ; )
    
  • PARI
    default(realprecision, 20080); x=suminf(k=0, 1/2^fibonacci(k)); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b124091.txt", n, " ", d)) \\ Harry J. Smith, May 04 2009

Formula

Equals Sum_{i>=0} 1/2^A000045(i).
Equals A084119 + 1.

Extensions

More terms from Robert G. Wilson v, Nov 26 2006