A140321 - OEIS

A140321

Decimal expansion of x-coordinate of fixed point of Hénon map for a=7/5 and b=3/10 where x is positive.

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

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OFFSET

0,1

COMMENTS

Henon attractor equation: (x=y+1-a*x^2, y=b*x, a=7/5, b=3/10), with solution (x=(sqrt(609)-7)/28, y=3*x/10).

There are two different fixed points of the Hénon map for a=7/5 and b=3/10. Sequence focuses on the decimal expansion of the x-coordinate of one of them. - Altug Alkan, Nov 19 2015

LINKS

Table of n, a(n) for n=0..99.

Wikipedia, Hénon map.

FORMULA

x = (sqrt(609) - 7)/28.

EXAMPLE

x = 0.63135447708950471168156023383569597544158647441012608539257671385...

MATHEMATICA

RealDigits[(Sqrt[609] - 7)/28, 10, 105][[1]] (* Amiram Eldar, Apr 29 2023 *)

PROG

(PARI) (sqrt(609)-7)/28 \\ Altug Alkan, Nov 19 2015

CROSSREFS

Sequence in context: A132615 A238260 A021617 * A019979 A085580 A092151

Adjacent sequences: A140318 A140319 A140320 * A140322 A140323 A140324

KEYWORD

cons,nonn

AUTHOR

Zak Seidov, May 26 2008

EXTENSIONS

Offset corrected R. J. Mathar, Jan 26 2009

Better definition from Altug Alkan, Nov 19 2015

STATUS

approved