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.

A084119 Decimal expansion of the Fibonacci binary number, Sum_{k>0} 1/2^F(k), where F(k) = A000045(k).

Original entry on oeis.org

1, 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
Offset: 1

Views

Author

Ralf Stephan, May 18 2003

Keywords

Comments

The Fibonacci binary number 1.41027879720... is known to be transcendental.

Examples

			1.410278797207865891794043024471063...
		

Crossrefs

Cf. A000045, A010056, A079586, A181313 (continued fraction), A124091 (essentially the same).

Programs

  • Mathematica
    RealDigits[N[Sum[1/2^Fibonacci[k], {k, 1, Infinity}], 120]][[1]] (* Amiram Eldar, Jun 12 2023 *)
  • PARI
    suminf(k=1,1/2^fibonacci(k)) \\ This gives the Fibonacci binary number, not the sequence
    
  • PARI
    default(realprecision, 20080); x=suminf(k=1, 1/2^fibonacci(k)); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b084119.txt", n, " ", d)); \\

A006518 Continued fraction for Sum_{k >= 2} 2^(-Fibonacci(k)).

Original entry on oeis.org

0, 1, 10, 6, 1, 6, 2, 14, 4, 124, 2, 1, 2, 2039, 1, 9, 1, 1, 1, 262111, 2, 8, 1, 1, 1, 3, 1, 536870655, 4, 16, 3, 1, 3, 7, 1, 140737488347135, 8, 128, 2, 1, 1, 1, 7, 2, 1, 9, 1
Offset: 0

Views

Author

Keywords

Examples

			0.91027879720786589179404302... = 0 + 1/(1 + 1/(10 + 1/(6 + 1/(1 + ...)))). - _Harry J. Smith_, May 04 2009
		

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • PARI
    { allocatemem(932245000); default(realprecision, 10000); x=suminf(k=2, 1/2^fibonacci(k)); c=contfrac(x); for (n=1, 565, write("b006518.txt", n-1, " ", c[n])); } \\ Harry J. Smith, May 04 2009

Formula

Interestingly, a(13)=2^11-2^3-1, a(19)=2^18-2^5-1, a(27)=2^29-2^8-1, a(35)=2^47-2^13-1. - Ralf Stephan, Jun 07 2005

A125600 Continued fraction expansion of constant defined in A124091.

Original entry on oeis.org

2, 2, 2, 3, 2, 28, 1, 13, 1, 2, 1, 123, 1, 6, 1, 2039, 2, 2, 6, 262111, 1, 35, 1, 1, 3, 536870655, 1, 2, 1, 15, 1, 3, 3, 1, 1, 1, 2, 140737488347135, 1, 1, 1, 1, 1, 127, 1, 7, 7, 1, 5, 2, 2, 75557863725914321321983, 1, 1, 2, 5, 1, 2047, 2, 2, 5, 1, 31, 6, 1, 1, 3, 2, 2
Offset: 0

Views

Author

Robert G. Wilson v, Nov 26 2006

Keywords

Comments

Progressively larger PQ's: 2, 3, 28, 123, 2039, 262111, 536870655, 140737488347135, 75557863725914321321983, 10633823966279326983230456465062887423, 803469022129495137770981046170581301261101460862599398686719, 8543948143683640329580086824678208458410818089426611079788166431288878284152542557401710898184191, ...,.

Crossrefs

Cf. A124091 (decimal expansion), A181313 (essentially the same), A006518.

Programs

  • Mathematica
    c = N[Sum[(1/2)^Fibonacci[i], {i, 0, Infinity}], 1000]; ContinuedFraction@c

Extensions

Offset changed by Andrew Howroyd, Aug 03 2024
Showing 1-3 of 3 results.