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.

A105393 Decimal expansion of sum of reciprocals of squares of Fibonacci numbers.

Original entry on oeis.org

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

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Author

Jonathan Vos Post, Apr 04 2005

Keywords

Comments

Known to be transcendental. - Benoit Cloitre, Jan 07 2006
Compare with Sum_{n >= 1} 1/(F(n)^2 + 1) = (5*sqrt(5) - 3)/6 and Sum_{n >= 3} 1/(F(n)^2 - 1) = (43 - 15*sqrt(5))/18. - Peter Bala, Nov 19 2019
Duverney et al. (1997) proved that this constant is transcendental. - Amiram Eldar, Oct 30 2020

Examples

			2.426320751167241187741569...
		

Crossrefs

Cf. A000045, A007598 (squares of Fibonacci numbers).

Programs

  • Mathematica
    RealDigits[Total[1/Fibonacci[Range[500]]^2],10,120][[1]] (* Harvey P. Dale, May 31 2016 *)
  • PARI
    sum(k=1,500,1./fibonacci(k)^2) \\ Benoit Cloitre, Jan 07 2006

Formula

Equals Sum_{k>=1} 1/F(k)^2 = 2.4263207511672411877... - Benoit Cloitre, Jan 07 2006

Extensions

More terms from Benoit Cloitre, Jan 07 2006