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 1-2 of 2 results.

A220812 Denominators of the Verhulst sequence x(n+1)=4*x(n)-3*x(n)^2, x(0)=1/10.

Original entry on oeis.org

10, 100, 10000, 100000000, 10000000000000000, 100000000000000000000000000000000, 10000000000000000000000000000000000000000000000000000000000000000
Offset: 0

Views

Author

Reinhard Zumkeller, Dec 22 2012

Keywords

References

  • H. O. Peitgen and P. H. Richter, The Beauty of Fractals. Springer, 1986, p. 23f.

Crossrefs

Cf. A051840, A220811 (numerators).

Programs

Formula

a(n) = 10^(2^n) = A011557(A000079(n)). - Reinhard Zumkeller, Dec 22 2012

A051840 Integer part of the Verhulst sequence x(n)=x(n-1)+3*(1-x(n-1))*x(n-1), x(0)=.1.

Original entry on oeis.org

0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0
Offset: 0

Views

Author

Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Dec 13 1999

Keywords

Comments

a(n) = floor(A220811(n)/A220812(n)). - Reinhard Zumkeller, Dec 22 2012

References

  • Peitgen, H.-O. and Richter, P. H., The Beauty of Fractals. Springer, 1986, p. 24.

Programs

  • Haskell
    a051840 n = a051840_list !! n
    a051840_list = map floor vs where
       vs = iterate (\x -> x * (4 - 3 * x)) 0.1
    -- Reinhard Zumkeller, Dec 22 2012
  • Mathematica
    NestList[ #*(4-3*#)&, 0.1, 103] // Floor (* Jean-François Alcover, Jan 16 2013 *)

Extensions

Data corrected for n > 37 by Reinhard Zumkeller, Dec 22 2012
Showing 1-2 of 2 results.